diff --git a/src/main/java/com/android/tools/r8/BaseCommand.java b/src/main/java/com/android/tools/r8/BaseCommand.java
index bf58365..3497778 100644
--- a/src/main/java/com/android/tools/r8/BaseCommand.java
+++ b/src/main/java/com/android/tools/r8/BaseCommand.java
@@ -5,6 +5,7 @@
 
 import com.android.tools.r8.dex.Constants;
 import com.android.tools.r8.utils.AndroidApp;
+import com.android.tools.r8.utils.OutputMode;
 import com.android.tools.r8.utils.FileUtils;
 import com.android.tools.r8.utils.InternalOptions;
 import java.io.IOException;
@@ -19,6 +20,7 @@
 
   private final AndroidApp app;
   private final Path outputPath;
+  private final OutputMode outputMode;
   private final CompilationMode mode;
   private final int minApiLevel;
 
@@ -28,16 +30,19 @@
     // All other fields are initialized with stub/invalid values.
     this.app = null;
     this.outputPath = null;
+    this.outputMode = OutputMode.Indexed;
     this.mode = null;
     this.minApiLevel = 0;
   }
 
-  BaseCommand(AndroidApp app, Path outputPath, CompilationMode mode, int minApiLevel) {
+  BaseCommand(AndroidApp app, Path outputPath,
+      OutputMode outputMode, CompilationMode mode, int minApiLevel) {
     assert app != null;
     assert mode != null;
     assert minApiLevel > 0;
     this.app = app;
     this.outputPath = outputPath;
+    this.outputMode = outputMode;
     this.mode = mode;
     this.minApiLevel = minApiLevel;
     // Print options are not set.
@@ -73,12 +78,17 @@
     return minApiLevel;
   }
 
+  public OutputMode getOutputMode() {
+    return outputMode;
+  }
+
   abstract static class Builder<C extends BaseCommand, B extends Builder<C, B>> {
 
     private boolean printHelp = false;
     private boolean printVersion = false;
     private final AndroidApp.Builder app;
     private Path outputPath = null;
+    private OutputMode outputMode = OutputMode.Indexed;
     private CompilationMode mode;
     private int minApiLevel = Constants.DEFAULT_ANDROID_API;
 
@@ -183,12 +193,23 @@
       return outputPath;
     }
 
+    /** Get the output mode. */
+    public OutputMode getOutputMode() {
+      return outputMode;
+    }
+
     /** Set an output path. Must be an existing directory or a non-existent zip file. */
     public B setOutputPath(Path outputPath) throws CompilationException {
       this.outputPath = FileUtils.validateOutputFile(outputPath);
       return self();
     }
 
+    /** Set an output mode. */
+    public B setOutputMode(OutputMode outputMode) {
+      this.outputMode = outputMode;
+      return self();
+    }
+
     /** Get the minimum API level (aka SDK version). */
     public int getMinApiLevel() {
       return minApiLevel;
diff --git a/src/main/java/com/android/tools/r8/BaseOutput.java b/src/main/java/com/android/tools/r8/BaseOutput.java
index 0f082c9..cb4d473 100644
--- a/src/main/java/com/android/tools/r8/BaseOutput.java
+++ b/src/main/java/com/android/tools/r8/BaseOutput.java
@@ -4,6 +4,7 @@
 package com.android.tools.r8;
 
 import com.android.tools.r8.utils.AndroidApp;
+import com.android.tools.r8.utils.OutputMode;
 import com.google.common.collect.ImmutableList;
 import java.io.IOException;
 import java.nio.file.Path;
@@ -11,9 +12,11 @@
 abstract class BaseOutput {
 
   private final AndroidApp app;
+  private final OutputMode outputMode;
 
-  BaseOutput(AndroidApp app) {
+  BaseOutput(AndroidApp app, OutputMode outputMode) {
     this.app = app;
+    this.outputMode = outputMode;
   }
 
   // Internal access to the underlying app.
@@ -21,6 +24,11 @@
     return app;
   }
 
+  // Internal access to the options.
+  public OutputMode getOutputMode() {
+    return outputMode;
+  }
+
   /**
    * Get the list of compiled DEX resources.
    *
diff --git a/src/main/java/com/android/tools/r8/D8.java b/src/main/java/com/android/tools/r8/D8.java
index 82831f3..0a0c976 100644
--- a/src/main/java/com/android/tools/r8/D8.java
+++ b/src/main/java/com/android/tools/r8/D8.java
@@ -59,8 +59,9 @@
    * @return the compilation result.
    */
   public static D8Output run(D8Command command) throws IOException {
-    D8Output output = new D8Output(
-        runForTesting(command.getInputApp(), command.getInternalOptions()).androidApp);
+    CompilationResult result = runForTesting(command.getInputApp(), command.getInternalOptions());
+    assert result != null;
+    D8Output output = new D8Output(result.androidApp, command.getOutputMode());
     if (command.getOutputPath() != null) {
       output.write(command.getOutputPath());
     }
@@ -78,8 +79,10 @@
    * @return the compilation result.
    */
   public static D8Output run(D8Command command, ExecutorService executor) throws IOException {
-    D8Output output = new D8Output(
-        runForTesting(command.getInputApp(), command.getInternalOptions(), executor).androidApp);
+    CompilationResult result = runForTesting(
+        command.getInputApp(), command.getInternalOptions(), executor);
+    assert result != null;
+    D8Output output = new D8Output(result.androidApp, command.getOutputMode());
     if (command.getOutputPath() != null) {
       output.write(command.getOutputPath());
     }
diff --git a/src/main/java/com/android/tools/r8/D8Command.java b/src/main/java/com/android/tools/r8/D8Command.java
index b4a83a4..a395530 100644
--- a/src/main/java/com/android/tools/r8/D8Command.java
+++ b/src/main/java/com/android/tools/r8/D8Command.java
@@ -7,6 +7,7 @@
 import com.android.tools.r8.utils.AndroidApp;
 import com.android.tools.r8.utils.InternalOptions;
 import com.android.tools.r8.utils.OffOrAuto;
+import com.android.tools.r8.utils.OutputMode;
 import com.google.common.collect.ImmutableList;
 import java.io.IOException;
 import java.nio.file.Path;
@@ -30,7 +31,6 @@
    * Builder for constructing a D8Command.
    */
   public static class Builder extends BaseCommand.Builder<D8Command, Builder> {
-
     private Builder() {
       super(CompilationMode.DEBUG);
     }
@@ -52,7 +52,8 @@
       if (isPrintHelp() || isPrintVersion()) {
         return new D8Command(isPrintHelp(), isPrintVersion());
       }
-      return new D8Command(getAppBuilder().build(), getOutputPath(), getMode(), getMinApiLevel());
+      return new D8Command(getAppBuilder().build(),
+          getOutputPath(), getOutputMode(), getMode(), getMinApiLevel());
     }
   }
 
@@ -67,6 +68,7 @@
       "  --lib <file>        # Add <file> as a library resource.",
       "  --classpath <file>  # Add <file> as a classpath resource.",
       "  --min-sdk-version   # minimum Android API level compatibility",
+      "  --file-per-class    # produce a separate dex file per class",
       "  --version           # print the version of d8.",
       "  --help              # print this message."));
 
@@ -103,6 +105,8 @@
         }
         builder.setMode(CompilationMode.RELEASE);
         modeSet = CompilationMode.RELEASE;
+      } else if (arg.equals("--file-per-class")) {
+        builder.setOutputMode(OutputMode.FilePerClass);
       } else if (arg.equals("--output")) {
         String output = args[++i];
         if (outputPath != null) {
@@ -126,8 +130,9 @@
     return builder.setOutputPath(outputPath);
   }
 
-  private D8Command(AndroidApp inputApp, Path outputPath, CompilationMode mode, int minApiLevel) {
-    super(inputApp, outputPath, mode, minApiLevel);
+  private D8Command(AndroidApp inputApp, Path outputPath,
+      OutputMode outputMode, CompilationMode mode, int minApiLevel) {
+    super(inputApp, outputPath, outputMode, mode, minApiLevel);
   }
 
   private D8Command(boolean printHelp, boolean printVersion) {
@@ -158,6 +163,7 @@
     internal.outline.enabled = false;
     internal.lazyClasspathLoading = true;
     internal.lazyLibraryLoading = true;
+    internal.outputMode = getOutputMode();
     return internal;
   }
 }
diff --git a/src/main/java/com/android/tools/r8/D8Output.java b/src/main/java/com/android/tools/r8/D8Output.java
index 84f8803..1910e9b 100644
--- a/src/main/java/com/android/tools/r8/D8Output.java
+++ b/src/main/java/com/android/tools/r8/D8Output.java
@@ -4,18 +4,19 @@
 package com.android.tools.r8;
 
 import com.android.tools.r8.utils.AndroidApp;
+import com.android.tools.r8.utils.OutputMode;
 import java.io.IOException;
 import java.nio.file.Path;
 
 /** Represents the output of a D8 compilation. */
 public class D8Output extends BaseOutput {
 
-  D8Output(AndroidApp app) {
-    super(app);
+  D8Output(AndroidApp app, OutputMode outputMode) {
+    super(app, outputMode);
   }
 
   @Override
   public void write(Path output) throws IOException {
-    getAndroidApp().write(output);
+    getAndroidApp().write(output, getOutputMode());
   }
 }
diff --git a/src/main/java/com/android/tools/r8/R8.java b/src/main/java/com/android/tools/r8/R8.java
index 3b89567..306f37b 100644
--- a/src/main/java/com/android/tools/r8/R8.java
+++ b/src/main/java/com/android/tools/r8/R8.java
@@ -26,7 +26,6 @@
 import com.android.tools.r8.shaking.AnnotationRemover;
 import com.android.tools.r8.shaking.DiscardedChecker;
 import com.android.tools.r8.shaking.Enqueuer;
-import com.android.tools.r8.shaking.Enqueuer.AppInfoWithLiveness;
 import com.android.tools.r8.shaking.MainDexListBuilder;
 import com.android.tools.r8.shaking.ProguardRuleParserException;
 import com.android.tools.r8.shaking.ProguardTypeMatcher;
@@ -40,6 +39,7 @@
 import com.android.tools.r8.utils.CfgPrinter;
 import com.android.tools.r8.utils.InternalOptions;
 import com.android.tools.r8.utils.InternalOptions.AttributeRemovalOptions;
+import com.android.tools.r8.utils.OutputMode;
 import com.android.tools.r8.utils.PackageDistribution;
 import com.android.tools.r8.utils.ThreadUtils;
 import com.android.tools.r8.utils.Timing;
@@ -384,7 +384,7 @@
     AndroidApp outputApp =
         runForTesting(command.getInputApp(), command.getInternalOptions()).androidApp;
     if (command.getOutputPath() != null) {
-      outputApp.write(command.getOutputPath());
+      outputApp.write(command.getOutputPath(), OutputMode.Indexed);
     }
     return outputApp;
   }
@@ -404,7 +404,7 @@
     AndroidApp outputApp =
         runForTesting(command.getInputApp(), command.getInternalOptions(), executor).androidApp;
     if (command.getOutputPath() != null) {
-      outputApp.write(command.getOutputPath());
+      outputApp.write(command.getOutputPath(), OutputMode.Indexed);
     }
     return outputApp;
   }
diff --git a/src/main/java/com/android/tools/r8/R8Command.java b/src/main/java/com/android/tools/r8/R8Command.java
index f70a295..9b44546 100644
--- a/src/main/java/com/android/tools/r8/R8Command.java
+++ b/src/main/java/com/android/tools/r8/R8Command.java
@@ -11,6 +11,7 @@
 import com.android.tools.r8.utils.AndroidApp;
 import com.android.tools.r8.utils.FileUtils;
 import com.android.tools.r8.utils.InternalOptions;
+import com.android.tools.r8.utils.OutputMode;
 import com.google.common.collect.ImmutableList;
 import java.io.IOException;
 import java.nio.file.Path;
@@ -158,6 +159,7 @@
       return new R8Command(
           getAppBuilder().build(),
           getOutputPath(),
+          getOutputMode(),
           mainDexKeepRules,
           configuration,
           getMode(),
@@ -296,6 +298,7 @@
   private R8Command(
       AndroidApp inputApp,
       Path outputPath,
+      OutputMode outputMode,
       ImmutableList<ProguardConfigurationRule> mainDexKeepRules,
       ProguardConfiguration proguardConfiguration,
       CompilationMode mode,
@@ -303,9 +306,10 @@
       boolean useTreeShaking,
       boolean useMinification,
       boolean ignoreMissingClasses) {
-    super(inputApp, outputPath, mode, minApiLevel);
+    super(inputApp, outputPath, outputMode, mode, minApiLevel);
     assert proguardConfiguration != null;
     assert mainDexKeepRules != null;
+    assert getOutputMode() == OutputMode.Indexed : "Only regular mode is supported in R8";
     this.mainDexKeepRules = mainDexKeepRules;
     this.proguardConfiguration = proguardConfiguration;
     this.useTreeShaking = useTreeShaking;
@@ -373,6 +377,7 @@
     internal.mainDexKeepRules = mainDexKeepRules;
     internal.keepRules = proguardConfiguration.getRules();
     internal.dontWarnPatterns = proguardConfiguration.getDontWarnPatterns();
+    internal.outputMode = getOutputMode();
     return internal;
   }
 }
diff --git a/src/main/java/com/android/tools/r8/Resource.java b/src/main/java/com/android/tools/r8/Resource.java
index 74236a0..c7760bb 100644
--- a/src/main/java/com/android/tools/r8/Resource.java
+++ b/src/main/java/com/android/tools/r8/Resource.java
@@ -6,6 +6,7 @@
 import com.google.common.io.Closer;
 import java.io.IOException;
 import java.io.InputStream;
+import java.util.Set;
 
 /** Represents application resources. */
 public interface Resource {
@@ -18,6 +19,12 @@
   /** Get the kind of the resource. */
   Kind getKind();
 
+  /**
+   * Returns the set of class descriptors for classes represented
+   * by the resource if known, or `null' otherwise.
+   */
+  Set<String> getClassDescriptors();
+
   /** Get the resource as a stream. */
   InputStream getStream(Closer closer) throws IOException;
 }
diff --git a/src/main/java/com/android/tools/r8/bisect/Bisect.java b/src/main/java/com/android/tools/r8/bisect/Bisect.java
index b48f268..1c76f46 100644
--- a/src/main/java/com/android/tools/r8/bisect/Bisect.java
+++ b/src/main/java/com/android/tools/r8/bisect/Bisect.java
@@ -13,6 +13,7 @@
 import com.android.tools.r8.graph.DexProgramClass;
 import com.android.tools.r8.utils.AndroidApp;
 import com.android.tools.r8.utils.InternalOptions;
+import com.android.tools.r8.utils.OutputMode;
 import com.android.tools.r8.utils.Timing;
 import com.google.common.io.CharStreams;
 import java.io.File;
@@ -180,7 +181,7 @@
     AppInfo appInfo = new AppInfo(app);
     ApplicationWriter writer = new ApplicationWriter(app, appInfo, options, null, null);
     AndroidApp outApp = writer.write(null, executor);
-    outApp.writeToDirectory(output);
+    outApp.writeToDirectory(output, OutputMode.Indexed);
   }
 
   public static void main(String[] args) throws Exception {
diff --git a/src/main/java/com/android/tools/r8/dex/ApplicationReader.java b/src/main/java/com/android/tools/r8/dex/ApplicationReader.java
index 8ab8921..4bf5cd9 100644
--- a/src/main/java/com/android/tools/r8/dex/ApplicationReader.java
+++ b/src/main/java/com/android/tools/r8/dex/ApplicationReader.java
@@ -91,14 +91,14 @@
       reader.read(DEFAULT_DEX_FILENAME, Resource.Kind.PROGRAM, input.getStream(closer));
     }
     for (InternalResource input : inputApp.getClassClasspathResources()) {
-      if (options.lazyClasspathLoading && input.getClassDescriptor() != null) {
+      if (options.lazyClasspathLoading && input.getSingleClassDescriptorOrNull() != null) {
         addLazyLoader(application, builder, input);
       } else {
         reader.read(DEFAULT_DEX_FILENAME, Resource.Kind.CLASSPATH, input.getStream(closer));
       }
     }
     for (InternalResource input : inputApp.getClassLibraryResources()) {
-      if (options.lazyLibraryLoading && input.getClassDescriptor() != null) {
+      if (options.lazyLibraryLoading && input.getSingleClassDescriptorOrNull() != null) {
         addLazyLoader(application, builder, input);
       } else {
         reader.read(DEFAULT_DEX_FILENAME, Resource.Kind.LIBRARY, input.getStream(closer));
@@ -109,7 +109,7 @@
   private void addLazyLoader(JarApplicationReader application,
       DexApplication.Builder builder, InternalResource resource) {
     // Generate expected DEX type.
-    String classDescriptor = resource.getClassDescriptor();
+    String classDescriptor = resource.getSingleClassDescriptorOrNull();
     assert classDescriptor != null;
     DexType type = options.itemFactory.createType(classDescriptor);
     LazyClassFileLoader newLoader = new LazyClassFileLoader(type, resource, application);
diff --git a/src/main/java/com/android/tools/r8/dex/ApplicationWriter.java b/src/main/java/com/android/tools/r8/dex/ApplicationWriter.java
index d86f929..db264ca 100644
--- a/src/main/java/com/android/tools/r8/dex/ApplicationWriter.java
+++ b/src/main/java/com/android/tools/r8/dex/ApplicationWriter.java
@@ -19,14 +19,12 @@
 import com.android.tools.r8.utils.AndroidApp;
 import com.android.tools.r8.utils.InternalOptions;
 import com.android.tools.r8.utils.PackageDistribution;
-import com.android.tools.r8.utils.ThreadUtils;
 import java.io.ByteArrayOutputStream;
 import java.io.IOException;
 import java.io.PrintStream;
 import java.io.PrintWriter;
 import java.io.Writer;
-import java.util.ArrayList;
-import java.util.List;
+import java.util.LinkedHashMap;
 import java.util.Map;
 import java.util.concurrent.ExecutionException;
 import java.util.concurrent.ExecutorService;
@@ -117,18 +115,23 @@
           VirtualFile.fileSetFrom(this, packageDistribution, executorService);
 
       // Write the dex files and the Proguard mapping file in parallel.
-      List<Future<byte[]>> dexDataFutures = new ArrayList<>();
+      LinkedHashMap<VirtualFile, Future<byte[]>> dexDataFutures = new LinkedHashMap<>();
       for (Integer index : newFiles.keySet()) {
         VirtualFile newFile = newFiles.get(index);
         if (!newFile.isEmpty()) {
-          dexDataFutures.add(executorService.submit(() -> writeDexFile(newFile)));
+          dexDataFutures.put(newFile, executorService.submit(() -> writeDexFile(newFile)));
         }
       }
 
       // Wait for all the spawned futures to terminate.
-      List<byte[]> dexData = ThreadUtils.awaitFutures(dexDataFutures);
       AndroidApp.Builder builder = AndroidApp.builder();
-      dexData.forEach(builder::addDexProgramData);
+      try {
+        for (Map.Entry<VirtualFile, Future<byte[]>> entry : dexDataFutures.entrySet()) {
+          builder.addDexProgramData(entry.getValue().get(), entry.getKey().getClassDescriptors());
+        }
+      } catch (InterruptedException e) {
+        throw new RuntimeException("Interrupted while waiting for future.", e);
+      }
       // Write the proguard map file after writing the dex files, as the map writer traverses
       // the DexProgramClass structures, which are destructively updated during dex file writing.
       byte[] proguardMapResult = writeProguardMapFile();
diff --git a/src/main/java/com/android/tools/r8/dex/VirtualFile.java b/src/main/java/com/android/tools/r8/dex/VirtualFile.java
index e575cee..ad5420d 100644
--- a/src/main/java/com/android/tools/r8/dex/VirtualFile.java
+++ b/src/main/java/com/android/tools/r8/dex/VirtualFile.java
@@ -24,6 +24,7 @@
 import com.android.tools.r8.utils.DescriptorUtils;
 import com.android.tools.r8.utils.FileUtils;
 import com.android.tools.r8.utils.InternalOptions;
+import com.android.tools.r8.utils.OutputMode;
 import com.android.tools.r8.utils.PackageDistribution;
 import com.android.tools.r8.utils.ThreadUtils;
 import com.google.common.collect.Iterators;
@@ -37,6 +38,7 @@
 import java.util.Collection;
 import java.util.Collections;
 import java.util.HashMap;
+import java.util.HashSet;
 import java.util.Iterator;
 import java.util.LinkedHashMap;
 import java.util.LinkedHashSet;
@@ -61,6 +63,7 @@
   private static final int MAX_PREFILL_ENTRIES = MAX_ENTRIES - 5000;
 
   private final int id;
+  private final Set<String> classDescriptors = new HashSet<>();
   private final VirtualFileIndexedItemCollection indexedItems;
   private final IndexedItemTransaction transaction;
 
@@ -70,6 +73,10 @@
     this.transaction = new IndexedItemTransaction(indexedItems, namingLens);
   }
 
+  public Set<String> getClassDescriptors() {
+    return classDescriptors;
+  }
+
   public static Map<Integer, VirtualFile> fileSetFrom(
       ApplicationWriter writer,
       PackageDistribution packageDistribution,
@@ -81,6 +88,20 @@
     DexApplication application = writer.application;
     InternalOptions options = writer.options;
     Map<Integer, VirtualFile> nameToFileMap = new LinkedHashMap<>();
+
+    if (options.outputMode == OutputMode.FilePerClass) {
+      assert packageDistribution == null :
+          "Cannot combine package distribution definition with file-per-class option.";
+      // Assign dedicated virtual files for all program classes.
+      for (DexProgramClass clazz : application.classes()) {
+        VirtualFile file = new VirtualFile(nameToFileMap.size(), writer.namingLens);
+        nameToFileMap.put(nameToFileMap.size(), file);
+        file.addClass(clazz);
+        file.commitTransaction();
+      }
+      return nameToFileMap;
+    }
+
     if (packageDistribution != null) {
       int maxReferencedIndex = packageDistribution.maxReferencedIndex();
       for (int index = 0; index <= maxReferencedIndex; index++) {
@@ -268,6 +289,7 @@
 
   private void addClass(DexProgramClass clazz) {
     transaction.addClassAndDependencies(clazz);
+    classDescriptors.add(clazz.type.descriptor.toString());
   }
 
   private static boolean isFull(int numberOfMethods, int numberOfFields, int maximum) {
diff --git a/src/main/java/com/android/tools/r8/graph/LazyClassFileLoader.java b/src/main/java/com/android/tools/r8/graph/LazyClassFileLoader.java
index d5fa09a..ce40d19 100644
--- a/src/main/java/com/android/tools/r8/graph/LazyClassFileLoader.java
+++ b/src/main/java/com/android/tools/r8/graph/LazyClassFileLoader.java
@@ -83,11 +83,11 @@
       JarClassFileReader reader = new JarClassFileReader(this.reader, this::addClass);
       reader.read(DEFAULT_DEX_FILENAME, resource.getKind(), resource.getStream(closer));
     } catch (IOException e) {
-      throw new CompilationError("Failed to load class: " + resource.getClassDescriptor(), e);
+      throw new CompilationError("Failed to load class: " + type.toSourceString(), e);
     }
 
     if (loadedClass == null) {
-      throw new Unreachable("Class is supposed to be loaded: " + resource.getClassDescriptor());
+      throw new Unreachable("Class is supposed to be loaded: " + type.toSourceString());
     }
 
     if (loadedClass.type != type) {
diff --git a/src/main/java/com/android/tools/r8/utils/AndroidApp.java b/src/main/java/com/android/tools/r8/utils/AndroidApp.java
index 85d5c57..5c15109 100644
--- a/src/main/java/com/android/tools/r8/utils/AndroidApp.java
+++ b/src/main/java/com/android/tools/r8/utils/AndroidApp.java
@@ -31,7 +31,9 @@
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collection;
+import java.util.Collections;
 import java.util.List;
+import java.util.Set;
 import java.util.zip.ZipEntry;
 import java.util.zip.ZipException;
 import java.util.zip.ZipInputStream;
@@ -234,51 +236,45 @@
   /**
    * Write the dex program resources and proguard resource to @code{output}.
    */
-  public void write(Path output) throws IOException {
-    write(output, false);
+  public void write(Path output, OutputMode outputMode) throws IOException {
+    write(output, outputMode, false);
   }
 
   /**
    * Write the dex program resources and proguard resource to @code{output}.
    */
-  public void write(Path output, boolean overwrite) throws IOException {
+  public void write(Path output, OutputMode outputMode, boolean overwrite) throws IOException {
     if (isArchive(output)) {
-      writeToZip(output);
+      writeToZip(output, outputMode, overwrite);
     } else {
-      writeToDirectory(output);
+      writeToDirectory(output, outputMode, overwrite);
     }
   }
 
   /**
    * Write the dex program resources and proguard resource to @code{directory}.
    */
-  public void writeToDirectory(Path directory) throws IOException {
-    writeToDirectory(directory, false);
+  public void writeToDirectory(Path directory, OutputMode outputMode) throws IOException {
+    writeToDirectory(directory, outputMode, false);
   }
 
   /**
    * Write the dex program resources and proguard resource to @code{directory}.
    */
-  public void writeToDirectory(Path directory, boolean overwrite) throws IOException {
+  public void writeToDirectory(
+      Path directory, OutputMode outputMode, boolean overwrite) throws IOException {
     CopyOption[] options = copyOptions(overwrite);
     try (Closer closer = Closer.create()) {
       List<InternalResource> dexProgramSources = getDexProgramResources();
       for (int i = 0; i < dexProgramSources.size(); i++) {
-        Files.copy(dexProgramSources.get(i).getStream(closer),
-            directory.resolve(getDexFileName(i)), options);
+        Path fileName = directory.resolve(outputMode.getFileName(dexProgramSources.get(i), i));
+        Files.copy(dexProgramSources.get(i).getStream(closer), fileName, options);
       }
       writeProguardMap(closer, directory, overwrite);
       writeProguardSeeds(closer, directory, overwrite);
     }
   }
 
-  /**
-   * Write the dex program resources to @code{archive} and the proguard resource as its sibling.
-   */
-  public void writeToZip(Path archive) throws IOException {
-    writeToZip(archive, false);
-  }
-
   public List<byte[]> writeToMemory() throws IOException {
     List<byte[]> dex = new ArrayList<>();
     try (Closer closer = Closer.create()) {
@@ -296,13 +292,21 @@
   /**
    * Write the dex program resources to @code{archive} and the proguard resource as its sibling.
    */
-  public void writeToZip(Path archive, boolean overwrite) throws IOException {
+  public void writeToZip(Path archive, OutputMode outputMode) throws IOException {
+    writeToZip(archive, outputMode, false);
+  }
+
+  /**
+   * Write the dex program resources to @code{archive} and the proguard resource as its sibling.
+   */
+  public void writeToZip(
+      Path archive, OutputMode outputMode, boolean overwrite) throws IOException {
     OpenOption[] options = openOptions(overwrite);
     try (Closer closer = Closer.create()) {
       try (ZipOutputStream out = new ZipOutputStream(Files.newOutputStream(archive, options))) {
         List<InternalResource> dexProgramSources = getDexProgramResources();
         for (int i = 0; i < dexProgramSources.size(); i++) {
-          ZipEntry zipEntry = new ZipEntry(getDexFileName(i));
+          ZipEntry zipEntry = new ZipEntry(outputMode.getFileName(dexProgramSources.get(i), i));
           byte[] bytes = ByteStreams.toByteArray(dexProgramSources.get(i).getStream(closer));
           zipEntry.setSize(bytes.length);
           out.putNextEntry(zipEntry);
@@ -338,10 +342,6 @@
     }
   }
 
-  private String getDexFileName(int index) {
-    return index == 0 ? "classes.dex" : ("classes" + (index + 1) + ".dex");
-  }
-
   private OpenOption[] openOptions(boolean overwrite) {
     return new OpenOption[]{
         overwrite ? StandardOpenOption.CREATE : StandardOpenOption.CREATE_NEW,
@@ -456,6 +456,14 @@
     }
 
     /**
+     * Add dex program-data with class descriptor.
+     */
+    public Builder addDexProgramData(byte[] data, Set<String> classDescriptors) {
+      dexSources.add(InternalResource.fromBytes(Resource.Kind.PROGRAM, data, classDescriptors));
+      return this;
+    }
+
+    /**
      * Add dex program-data.
      */
     public Builder addDexProgramData(byte[]... data) {
@@ -577,8 +585,9 @@
             dexSources.add(InternalResource.fromBytes(kind, ByteStreams.toByteArray(stream)));
           } else if (isClassFile(name)) {
             containsClassData = true;
+            String descriptor = guessTypeDescriptor(name);
             classSources.add(InternalResource.fromBytes(
-                kind, ByteStreams.toByteArray(stream), guessTypeDescriptor(name)));
+                kind, ByteStreams.toByteArray(stream), Collections.singleton(descriptor)));
           }
         }
       } catch (ZipException e) {
diff --git a/src/main/java/com/android/tools/r8/utils/InternalOptions.java b/src/main/java/com/android/tools/r8/utils/InternalOptions.java
index 7f13315..3f8d992 100644
--- a/src/main/java/com/android/tools/r8/utils/InternalOptions.java
+++ b/src/main/java/com/android/tools/r8/utils/InternalOptions.java
@@ -57,6 +57,9 @@
   // Defines try-with-resources rewriter behavior.
   public OffOrAuto tryWithResourcesDesugaring = OffOrAuto.Off;
 
+  // Application writing mode.
+  public OutputMode outputMode = OutputMode.Indexed;
+
   public boolean useTreeShaking = true;
 
   public boolean printCfg = false;
diff --git a/src/main/java/com/android/tools/r8/utils/InternalResource.java b/src/main/java/com/android/tools/r8/utils/InternalResource.java
index 2d9bdb9..9181092 100644
--- a/src/main/java/com/android/tools/r8/utils/InternalResource.java
+++ b/src/main/java/com/android/tools/r8/utils/InternalResource.java
@@ -11,8 +11,10 @@
 import java.io.IOException;
 import java.io.InputStream;
 import java.nio.file.Path;
+import java.util.Set;
 
-/** Internal resource class that is not intended for use from the outside.
+/**
+ * Internal resource class that is not intended for use from the outside.
  *
  * <p>This is only here to hide the creation and class descriptor methods
  * from the javadoc for the D8 API. If we decide to expose those methods
@@ -26,9 +28,6 @@
     this.kind = kind;
   }
 
-  /** Returns class descriptor if known, otherwise returns null. */
-  public abstract String getClassDescriptor();
-
   /** Get the kind of the resource. */
   public Kind getKind() {
     return kind;
@@ -45,8 +44,18 @@
   }
 
   /** Create an application resource for a given content, kind and type descriptor. */
-  public static InternalResource fromBytes(Kind kind, byte[] bytes, String typeDescriptor) {
-    return new ByteResource(kind, bytes, typeDescriptor);
+  public static InternalResource fromBytes(Kind kind, byte[] bytes, Set<String> typeDescriptors) {
+    return new ByteResource(kind, bytes, typeDescriptors);
+  }
+
+  /**
+   * If the resource represents a single class returns
+   * its descriptor, returns `null` otherwise.
+   */
+  public String getSingleClassDescriptorOrNull() {
+    Set<String> descriptors = getClassDescriptors();
+    return (descriptors == null) || (descriptors.size() != 1)
+        ? null : descriptors.iterator().next();
   }
 
   /** File based application resource. */
@@ -60,7 +69,7 @@
     }
 
     @Override
-    public String getClassDescriptor() {
+    public Set<String> getClassDescriptors() {
       return null;
     }
 
@@ -72,19 +81,19 @@
 
   /** Byte content based application resource. */
   private static class ByteResource extends InternalResource {
-    final String classDescriptor;
+    final Set<String> classDescriptors;
     final byte[] bytes;
 
-    ByteResource(Kind kind, byte[] bytes, String classDescriptor) {
+    ByteResource(Kind kind, byte[] bytes, Set<String> classDescriptors) {
       super(kind);
       assert bytes != null;
-      this.classDescriptor = classDescriptor;
+      this.classDescriptors = classDescriptors;
       this.bytes = bytes;
     }
 
     @Override
-    public String getClassDescriptor() {
-      return classDescriptor;
+    public Set<String> getClassDescriptors() {
+      return classDescriptors;
     }
 
     @Override
diff --git a/src/main/java/com/android/tools/r8/utils/OutputMode.java b/src/main/java/com/android/tools/r8/utils/OutputMode.java
new file mode 100644
index 0000000..c27429a
--- /dev/null
+++ b/src/main/java/com/android/tools/r8/utils/OutputMode.java
@@ -0,0 +1,28 @@
+// Copyright (c) 2017, the R8 project authors. Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+package com.android.tools.r8.utils;
+
+import com.android.tools.r8.Resource;
+
+/** Defines way the output is formed. */
+public enum OutputMode {
+  Indexed {
+    @Override
+    String getFileName(Resource resource, int index) {
+      return index == 0 ? "classes.dex" : ("classes" + (index + 1) + ".dex");
+    }
+  },
+  FilePerClass {
+    @Override
+    String getFileName(Resource resource, int index) {
+      assert resource instanceof InternalResource;
+      String classDescriptor = ((InternalResource) resource).getSingleClassDescriptorOrNull();
+      assert classDescriptor != null;
+      assert !classDescriptor.contains(".");
+      return DescriptorUtils.descriptorToJavaType(classDescriptor) + ".dex";
+    }
+  };
+
+  abstract String getFileName(Resource resource, int index);
+}
diff --git a/src/test/examplesAndroidO/incremental/IncrementallyCompiled.java b/src/test/examplesAndroidO/incremental/IncrementallyCompiled.java
new file mode 100644
index 0000000..848528e
--- /dev/null
+++ b/src/test/examplesAndroidO/incremental/IncrementallyCompiled.java
@@ -0,0 +1,20 @@
+// Copyright (c) 2017, the R8 project authors. Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+package incremental;
+
+public class IncrementallyCompiled {
+  class A implements B {
+    class AB implements B.BA {
+    }
+  }
+
+  interface B {
+    interface BA {
+    }
+  }
+
+  static class C {
+  }
+}
+
diff --git a/src/test/java/com/android/tools/r8/D8IncrementalRunExamplesAndroidOTest.java b/src/test/java/com/android/tools/r8/D8IncrementalRunExamplesAndroidOTest.java
index a5e944a..4fd3276 100644
--- a/src/test/java/com/android/tools/r8/D8IncrementalRunExamplesAndroidOTest.java
+++ b/src/test/java/com/android/tools/r8/D8IncrementalRunExamplesAndroidOTest.java
@@ -4,16 +4,33 @@
 
 package com.android.tools.r8;
 
+import static com.android.tools.r8.utils.FileUtils.JAR_EXTENSION;
+
 import com.android.tools.r8.errors.CompilationError;
 import com.android.tools.r8.errors.InternalCompilerError;
 import com.android.tools.r8.errors.Unimplemented;
+import com.android.tools.r8.utils.AndroidApp;
+import com.android.tools.r8.utils.InternalResource;
+import com.android.tools.r8.utils.OffOrAuto;
+import com.android.tools.r8.utils.OutputMode;
+import com.beust.jcommander.internal.Lists;
+import com.google.common.io.Closer;
+import java.io.ByteArrayOutputStream;
 import java.io.File;
+import java.io.IOException;
+import java.io.InputStream;
 import java.nio.file.Path;
 import java.nio.file.Paths;
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.Collections;
 import java.util.List;
+import java.util.Map;
+import java.util.SortedMap;
+import java.util.TreeMap;
 import java.util.function.UnaryOperator;
+import org.junit.Assert;
+import org.junit.Test;
 
 public class D8IncrementalRunExamplesAndroidOTest
     extends RunExamplesAndroidOTest<D8Command.Builder> {
@@ -31,18 +48,53 @@
 
     @Override
     void build(Path testJarFile, Path out) throws Throwable {
-      // Collect classes and compile separately.
-      List<String> classFiles = collectClassFiles(testJarFile);
-      List<String> dexFiles = new ArrayList<>();
-      for (int i = 0; i < classFiles.size(); i++) {
-        Path indexedOut = Paths.get(
-            out.getParent().toString(), out.getFileName() + "." + i + ".zip");
-        compile(testJarFile.toString(), Collections.singletonList(classFiles.get(i)), indexedOut);
-        dexFiles.add(indexedOut.toString());
-      }
+      Map<String, Resource> files = compileClassesTogether(testJarFile, null);
+      mergeClassFiles(Lists.newArrayList(files.values()), out);
+    }
 
-      // When compiled add files separately, merge them.
-      compile(null, dexFiles, out);
+    // Dex classes separately.
+    SortedMap<String, Resource> compileClassesSeparately(Path testJarFile) throws Throwable {
+      TreeMap<String, Resource> fileToResource = new TreeMap<>();
+      List<String> classFiles = collectClassFiles(testJarFile);
+      for (String classFile : classFiles) {
+        AndroidApp app = compileClassFiles(
+            testJarFile.toString(), Collections.singletonList(classFile), null, OutputMode.Indexed);
+        assert app.getDexProgramResources().size() == 1;
+        fileToResource.put(
+            makeRelative(testJarFile, Paths.get(classFile)).toString(),
+            app.getDexProgramResources().get(0));
+      }
+      return fileToResource;
+    }
+
+    // Dex classes in one D8 invocation.
+    SortedMap<String, Resource> compileClassesTogether(
+        Path testJarFile, Path output) throws Throwable {
+      TreeMap<String, Resource> fileToResource = new TreeMap<>();
+      List<String> classFiles = collectClassFiles(testJarFile);
+      AndroidApp app = compileClassFiles(
+          testJarFile.toString(), classFiles, output, OutputMode.FilePerClass);
+      for (InternalResource resource : app.getDexProgramResources()) {
+        String classDescriptor = resource.getSingleClassDescriptorOrNull();
+        Assert.assertNotNull("Add resources are expected to have a descriptor", classDescriptor);
+        classDescriptor = classDescriptor.substring(1, classDescriptor.length() - 1);
+        fileToResource.put(classDescriptor + ".class", resource);
+      }
+      return fileToResource;
+    }
+
+    private Path makeRelative(Path testJarFile, Path classFile) {
+      classFile = classFile.toAbsolutePath();
+      Path regularParent =
+          testJarFile.getParent().resolve(Paths.get("classes")).toAbsolutePath();
+      Path legacyParent = regularParent.resolve(Paths.get("..",
+          regularParent.getFileName().toString() + "Legacy", "classes")).toAbsolutePath();
+
+      if (classFile.startsWith(regularParent)) {
+        return regularParent.relativize(classFile);
+      }
+      Assert.assertTrue(classFile.startsWith(legacyParent));
+      return legacyParent.relativize(classFile);
     }
 
     private List<String> collectClassFiles(Path testJarFile) {
@@ -73,21 +125,48 @@
       }
     }
 
-    private void compile(String classpath, List<String> inputFiles, Path out) throws Throwable {
+    AndroidApp compileClassFiles(String classpath,
+        List<String> inputFiles, Path output, OutputMode outputMode) throws Throwable {
       D8Command.Builder builder = D8Command.builder();
-      if (classpath != null) {
-        builder.addClasspathFiles(Paths.get(classpath));
-      }
+      builder = builder.addClasspathFiles(Paths.get(classpath));
       for (String inputFile : inputFiles) {
-        builder.addProgramFiles(Paths.get(inputFile));
+        builder = builder.addProgramFiles(Paths.get(inputFile));
       }
       for (UnaryOperator<D8Command.Builder> transformation : builderTransformations) {
         builder = transformation.apply(builder);
       }
-      builder.addLibraryFiles(Paths.get(ToolHelper.getAndroidJar(builder.getMinApiLevel())));
-      D8Command command = builder.setOutputPath(out).build();
+      builder = builder.setOutputMode(outputMode);
+      builder = builder.addLibraryFiles(
+          Paths.get(ToolHelper.getAndroidJar(builder.getMinApiLevel())));
+      if (output != null) {
+        builder = builder.setOutputPath(output);
+      }
+      D8Command command = builder.build();
       try {
-        ToolHelper.runD8(command, this::combinedOptionConsumer);
+        return ToolHelper.runD8(command, this::combinedOptionConsumer);
+      } catch (Unimplemented | CompilationError | InternalCompilerError re) {
+        throw re;
+      } catch (RuntimeException re) {
+        throw re.getCause() == null ? re : re.getCause();
+      }
+    }
+
+    Resource mergeClassFiles(List<Resource> dexFiles, Path out) throws Throwable {
+      D8Command.Builder builder = D8Command.builder();
+      for (Resource dexFile : dexFiles) {
+        builder.addDexProgramData(readFromResource(dexFile));
+      }
+      for (UnaryOperator<D8Command.Builder> transformation : builderTransformations) {
+        builder = transformation.apply(builder);
+      }
+      if (out != null) {
+        builder = builder.setOutputPath(out);
+      }
+      D8Command command = builder.build();
+      try {
+        AndroidApp app = ToolHelper.runD8(command, this::combinedOptionConsumer);
+        assert app.getDexProgramResources().size() == 1;
+        return app.getDexProgramResources().get(0);
       } catch (Unimplemented | CompilationError | InternalCompilerError re) {
         throw re;
       } catch (RuntimeException re) {
@@ -96,8 +175,102 @@
     }
   }
 
+  @Test
+  public void dexPerClassFileNoDesugaring() throws Throwable {
+    String testName = "dexPerClassFileNoDesugaring";
+    String testPackage = "incremental";
+    String mainClass = "IncrementallyCompiled";
+
+    Path inputJarFile = Paths.get(EXAMPLE_DIR, testPackage + JAR_EXTENSION);
+
+    D8IncrementalTestRunner test = test(testName, testPackage, mainClass);
+
+    Map<String, Resource> compiledSeparately = test.compileClassesSeparately(inputJarFile);
+    Map<String, Resource> compiledTogether = test.compileClassesTogether(inputJarFile, null);
+    Assert.assertEquals(compiledSeparately.size(), compiledTogether.size());
+
+    for (Map.Entry<String, Resource> entry : compiledSeparately.entrySet()) {
+      Resource otherResource = compiledTogether.get(entry.getKey());
+      Assert.assertNotNull(otherResource);
+      Assert.assertArrayEquals(readFromResource(entry.getValue()), readFromResource(otherResource));
+    }
+
+    Resource mergedFromCompiledSeparately =
+        test.mergeClassFiles(Lists.newArrayList(compiledSeparately.values()), null);
+    Resource mergedFromCompiledTogether =
+        test.mergeClassFiles(Lists.newArrayList(compiledTogether.values()), null);
+    Assert.assertArrayEquals(
+        readFromResource(mergedFromCompiledSeparately),
+        readFromResource(mergedFromCompiledTogether));
+  }
+
+  @Test
+  public void dexPerClassFileWithDesugaring() throws Throwable {
+    String testName = "dexPerClassFileWithDesugaring";
+    String testPackage = "lambdadesugaringnplus";
+    String mainClass = "LambdasWithStaticAndDefaultMethods";
+
+    Path inputJarFile = Paths.get(EXAMPLE_DIR, testPackage + JAR_EXTENSION);
+
+    D8IncrementalTestRunner test = test(testName, testPackage, mainClass);
+    test.withInterfaceMethodDesugaring(OffOrAuto.Auto);
+
+    Resource mergedFromCompiledSeparately =
+        test.mergeClassFiles(Lists.newArrayList(
+            test.compileClassesSeparately(inputJarFile).values()), null);
+    Resource mergedFromCompiledTogether =
+        test.mergeClassFiles(Lists.newArrayList(
+            test.compileClassesTogether(inputJarFile, null).values()), null);
+
+    Assert.assertArrayEquals(
+        readFromResource(mergedFromCompiledSeparately),
+        readFromResource(mergedFromCompiledTogether));
+  }
+
+  @Test
+  public void dexPerClassFileOutputFiles() throws Throwable {
+    String testName = "dexPerClassFileNoDesugaring";
+    String testPackage = "incremental";
+    String mainClass = "IncrementallyCompiled";
+
+    Path out = temp.getRoot().toPath();
+
+    Path inputJarFile = Paths.get(EXAMPLE_DIR, testPackage + JAR_EXTENSION);
+
+    D8IncrementalTestRunner test = test(testName, testPackage, mainClass);
+    test.compileClassesTogether(inputJarFile, out);
+
+    String[] dexFiles = out.toFile().list();
+    assert dexFiles != null;
+    Arrays.sort(dexFiles);
+
+    String[] expectedFileNames = {
+        "incremental.IncrementallyCompiled$A$AB.dex",
+        "incremental.IncrementallyCompiled$A.dex",
+        "incremental.IncrementallyCompiled$B$BA.dex",
+        "incremental.IncrementallyCompiled$B.dex",
+        "incremental.IncrementallyCompiled$C.dex",
+        "incremental.IncrementallyCompiled.dex"
+    };
+
+    Assert.assertArrayEquals(expectedFileNames, dexFiles);
+  }
+
   @Override
-  TestRunner test(String testName, String packageName, String mainClass) {
+  D8IncrementalTestRunner test(String testName, String packageName, String mainClass) {
     return new D8IncrementalTestRunner(testName, packageName, mainClass);
   }
+
+  static byte[] readFromResource(Resource resource) throws IOException {
+    ByteArrayOutputStream output = new ByteArrayOutputStream();
+    byte[] buffer = new byte[16384];
+    try (Closer closer = Closer.create()) {
+      InputStream stream = resource.getStream(closer);
+      int read;
+      while ((read = stream.read(buffer, 0, buffer.length)) != -1) {
+        output.write(buffer, 0, read);
+      }
+    }
+    return output.toByteArray();
+  }
 }
diff --git a/src/test/java/com/android/tools/r8/TestBase.java b/src/test/java/com/android/tools/r8/TestBase.java
index bcb9f7d..333e77b 100644
--- a/src/test/java/com/android/tools/r8/TestBase.java
+++ b/src/test/java/com/android/tools/r8/TestBase.java
@@ -11,6 +11,7 @@
 import com.android.tools.r8.utils.AndroidApp;
 import com.android.tools.r8.utils.FileUtils;
 import com.android.tools.r8.utils.InternalOptions;
+import com.android.tools.r8.utils.OutputMode;
 import com.google.common.collect.ImmutableList;
 import com.google.common.io.ByteStreams;
 import java.io.File;
@@ -121,7 +122,7 @@
    */
   protected String runOnArt(AndroidApp app, Class mainClass) throws IOException {
     Path out = File.createTempFile("junit", ".zip", temp.getRoot()).toPath();
-    app.writeToZip(out, true);
+    app.writeToZip(out, OutputMode.Indexed, true);
     return ToolHelper.runArtNoVerificationErrors(
         ImmutableList.of(out.toString()), mainClass.getCanonicalName(), null);
   }
diff --git a/src/test/java/com/android/tools/r8/ToolHelper.java b/src/test/java/com/android/tools/r8/ToolHelper.java
index 739d90c..425dab7 100644
--- a/src/test/java/com/android/tools/r8/ToolHelper.java
+++ b/src/test/java/com/android/tools/r8/ToolHelper.java
@@ -14,6 +14,7 @@
 import com.android.tools.r8.utils.AndroidApp;
 import com.android.tools.r8.utils.InternalOptions;
 import com.android.tools.r8.utils.ListUtils;
+import com.android.tools.r8.utils.OutputMode;
 import com.android.tools.r8.utils.Timing;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableMap;
@@ -454,7 +455,7 @@
     }
     CompilationResult result = R8.runForTesting(app, options);
     if (command.getOutputPath() != null) {
-      result.androidApp.write(command.getOutputPath());
+      result.androidApp.write(command.getOutputPath(), OutputMode.Indexed);
     }
     return result;
   }
@@ -495,7 +496,7 @@
     }
     AndroidApp result = D8.runForTesting(command.getInputApp(), options).androidApp;
     if (command.getOutputPath() != null) {
-      result.write(command.getOutputPath());
+      result.write(command.getOutputPath(), command.getOutputMode());
     }
     return result;
   }
diff --git a/src/test/java/com/android/tools/r8/debuginfo/DebugInfoTestBase.java b/src/test/java/com/android/tools/r8/debuginfo/DebugInfoTestBase.java
index c16291a..9868437 100644
--- a/src/test/java/com/android/tools/r8/debuginfo/DebugInfoTestBase.java
+++ b/src/test/java/com/android/tools/r8/debuginfo/DebugInfoTestBase.java
@@ -12,6 +12,7 @@
 import com.android.tools.r8.ToolHelper.ProcessResult;
 import com.android.tools.r8.naming.MemberNaming.MethodSignature;
 import com.android.tools.r8.utils.AndroidApp;
+import com.android.tools.r8.utils.OutputMode;
 import com.google.common.collect.ImmutableList;
 import java.io.IOException;
 import java.nio.file.Path;
@@ -49,7 +50,7 @@
 
   protected String runOnArt(AndroidApp app, String main) throws IOException {
     Path out = temp.getRoot().toPath().resolve("out.zip");
-    app.writeToZip(out, true);
+    app.writeToZip(out, OutputMode.Indexed, true);
     return ToolHelper.runArtNoVerificationErrors(ImmutableList.of(out.toString()), main, null);
   }
 
diff --git a/src/test/java/com/android/tools/r8/internal/CompilationTestBase.java b/src/test/java/com/android/tools/r8/internal/CompilationTestBase.java
index 4b2ece0..80a1324 100644
--- a/src/test/java/com/android/tools/r8/internal/CompilationTestBase.java
+++ b/src/test/java/com/android/tools/r8/internal/CompilationTestBase.java
@@ -18,6 +18,7 @@
 import com.android.tools.r8.utils.ArtErrorParser.ArtErrorParserException;
 import com.android.tools.r8.utils.DexInspector;
 import com.android.tools.r8.utils.ListUtils;
+import com.android.tools.r8.utils.OutputMode;
 import java.io.File;
 import java.io.IOException;
 import java.nio.file.Path;
@@ -78,7 +79,7 @@
     }
     Path out = temp.getRoot().toPath().resolve("all.zip");
     Path oatFile = temp.getRoot().toPath().resolve("all.oat");
-    outputApp.writeToZip(out);
+    outputApp.writeToZip(out, OutputMode.Indexed);
     try {
       ToolHelper.runDex2Oat(out, oatFile);
       return outputApp;
diff --git a/src/test/java/com/android/tools/r8/internal/R8GMSCoreDeterministicTest.java b/src/test/java/com/android/tools/r8/internal/R8GMSCoreDeterministicTest.java
index 1481bc8..d9314d8 100644
--- a/src/test/java/com/android/tools/r8/internal/R8GMSCoreDeterministicTest.java
+++ b/src/test/java/com/android/tools/r8/internal/R8GMSCoreDeterministicTest.java
@@ -12,6 +12,7 @@
 import com.android.tools.r8.shaking.ProguardRuleParserException;
 import com.android.tools.r8.utils.AndroidApp;
 import com.android.tools.r8.utils.InternalResource;
+import com.android.tools.r8.utils.OutputMode;
 import com.google.common.io.ByteStreams;
 import com.google.common.io.Closer;
 import java.io.IOException;
@@ -57,7 +58,7 @@
     // Check that the generated bytecode runs through the dex2oat verifier with no errors.
     Path combinedInput = temp.getRoot().toPath().resolve("all.jar");
     Path oatFile = temp.getRoot().toPath().resolve("all.oat");
-    app1.writeToZip(combinedInput);
+    app1.writeToZip(combinedInput, OutputMode.Indexed);
     ToolHelper.runDex2Oat(combinedInput, oatFile);
   }
 }
diff --git a/src/test/java/com/android/tools/r8/jasmin/JasminTestBase.java b/src/test/java/com/android/tools/r8/jasmin/JasminTestBase.java
index 7db5451..615e289 100644
--- a/src/test/java/com/android/tools/r8/jasmin/JasminTestBase.java
+++ b/src/test/java/com/android/tools/r8/jasmin/JasminTestBase.java
@@ -16,6 +16,7 @@
 import com.android.tools.r8.shaking.ProguardRuleParserException;
 import com.android.tools.r8.utils.AndroidApp;
 import com.android.tools.r8.utils.InternalOptions;
+import com.android.tools.r8.utils.OutputMode;
 import com.android.tools.r8.utils.StringUtils;
 import com.google.common.collect.ImmutableList;
 import jasmin.ClassFile;
@@ -121,7 +122,7 @@
 
   protected String runOnArt(AndroidApp app, String main) throws IOException {
     Path out = temp.getRoot().toPath().resolve("out.zip");
-    app.writeToZip(out);
+    app.writeToZip(out, OutputMode.Indexed);
     return ToolHelper.runArtNoVerificationErrors(ImmutableList.of(out.toString()), main, null);
   }
 
diff --git a/src/test/java/com/android/tools/r8/maindexlist/MainDexListTests.java b/src/test/java/com/android/tools/r8/maindexlist/MainDexListTests.java
index 115aabd..29cef19 100644
--- a/src/test/java/com/android/tools/r8/maindexlist/MainDexListTests.java
+++ b/src/test/java/com/android/tools/r8/maindexlist/MainDexListTests.java
@@ -49,6 +49,7 @@
 import com.android.tools.r8.utils.InternalOptions;
 import com.android.tools.r8.utils.ListUtils;
 import com.android.tools.r8.utils.MainDexList;
+import com.android.tools.r8.utils.OutputMode;
 import com.android.tools.r8.utils.ThreadUtils;
 import com.android.tools.r8.utils.Timing;
 import com.google.common.collect.ImmutableList;
@@ -108,7 +109,7 @@
     }
     AndroidApp generated = generateApplication(TWO_LARGE_CLASSES, MAX_METHOD_COUNT);
     if (regenerateApplications) {
-      generated.write(getTwoLargeClassesAppPath(), true);
+      generated.write(getTwoLargeClassesAppPath(), OutputMode.Indexed, true);
     } else {
       AndroidApp cached = AndroidApp.fromProgramFiles(getTwoLargeClassesAppPath());
       compareToCachedVersion(cached, generated, TWO_LARGE_CLASSES_APP);
@@ -123,7 +124,7 @@
     }
     AndroidApp generated = generateApplication(MANY_CLASSES, 1);
     if (regenerateApplications) {
-      generated.write(getManyClassesAppPath(), true);
+      generated.write(getManyClassesAppPath(), OutputMode.Indexed, true);
     } else {
       AndroidApp cached = AndroidApp.fromProgramFiles(getManyClassesAppPath());
       compareToCachedVersion(cached, generated, MANY_CLASSES_APP);
diff --git a/src/test/java/com/android/tools/r8/smali/SmaliTestBase.java b/src/test/java/com/android/tools/r8/smali/SmaliTestBase.java
index 314adb1..3665a86 100644
--- a/src/test/java/com/android/tools/r8/smali/SmaliTestBase.java
+++ b/src/test/java/com/android/tools/r8/smali/SmaliTestBase.java
@@ -28,6 +28,7 @@
 import com.android.tools.r8.utils.DexInspector.ClassSubject;
 import com.android.tools.r8.utils.DexInspector.MethodSubject;
 import com.android.tools.r8.utils.InternalOptions;
+import com.android.tools.r8.utils.OutputMode;
 import com.android.tools.r8.utils.Smali;
 import com.android.tools.r8.utils.Timing;
 import com.google.common.collect.Iterables;
@@ -452,7 +453,7 @@
       AndroidApp app = writeDex(application, options);
       Path out = temp.getRoot().toPath().resolve("run-art-input.zip");
       // TODO(sgjesse): Pass in a unique temp directory for each run.
-      app.writeToZip(out, true);
+      app.writeToZip(out, OutputMode.Indexed, true);
       return ToolHelper.runArtNoVerificationErrors(out.toString(), DEFAULT_MAIN_CLASS_NAME);
     } catch (IOException e) {
       throw new RuntimeException(e);
@@ -464,7 +465,7 @@
       AndroidApp app = writeDex(application, options);
       Path dexOut = temp.getRoot().toPath().resolve("run-dex2oat-input.zip");
       Path oatFile = temp.getRoot().toPath().resolve("oat-file");
-      app.writeToZip(dexOut);
+      app.writeToZip(dexOut, OutputMode.Indexed);
       ToolHelper.runDex2Oat(dexOut, oatFile);
     } catch (IOException e) {
       throw new RuntimeException(e);