diff --git a/src/main/java/com/android/tools/r8/BaseCompilerCommand.java b/src/main/java/com/android/tools/r8/BaseCompilerCommand.java
index 5e8f975..7645242 100644
--- a/src/main/java/com/android/tools/r8/BaseCompilerCommand.java
+++ b/src/main/java/com/android/tools/r8/BaseCompilerCommand.java
@@ -136,7 +136,7 @@
 
     protected void validate() throws CompilationException {
       super.validate();
-      if (getAppBuilder().hasMainDexList() && outputMode == OutputMode.FilePerClass) {
+      if (getAppBuilder().hasMainDexList() && outputMode == OutputMode.FilePerInputClass) {
         throw new CompilationException(
             "Option --main-dex-list cannot be used with --file-per-class");
       }
diff --git a/src/main/java/com/android/tools/r8/D8Command.java b/src/main/java/com/android/tools/r8/D8Command.java
index 76779bb..f2aebc7 100644
--- a/src/main/java/com/android/tools/r8/D8Command.java
+++ b/src/main/java/com/android/tools/r8/D8Command.java
@@ -158,7 +158,7 @@
           builder.setMode(CompilationMode.RELEASE);
           modeSet = CompilationMode.RELEASE;
         } else if (arg.equals("--file-per-class")) {
-          builder.setOutputMode(OutputMode.FilePerClass);
+          builder.setOutputMode(OutputMode.FilePerInputClass);
         } else if (arg.equals("--output")) {
           String output = args[++i];
           if (outputPath != null) {
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 46ee85c..58c3a5b 100644
--- a/src/main/java/com/android/tools/r8/dex/ApplicationWriter.java
+++ b/src/main/java/com/android/tools/r8/dex/ApplicationWriter.java
@@ -138,10 +138,10 @@
 
       // Distribute classes into dex files.
       VirtualFile.Distributor distributor = null;
-      if (options.outputMode == OutputMode.FilePerClass) {
+      if (options.outputMode == OutputMode.FilePerInputClass) {
         assert packageDistribution == null :
             "Cannot combine package distribution definition with file-per-class option.";
-        distributor = new VirtualFile.FilePerClassDistributor(this);
+        distributor = new VirtualFile.FilePerInputClassDistributor(this);
       } else if (!options.canUseMultidex()
           && options.mainDexKeepRules.isEmpty()
           && application.mainDexList.isEmpty()) {
@@ -178,7 +178,15 @@
       AndroidApp.Builder builder = AndroidApp.builder();
       try {
         for (Map.Entry<VirtualFile, Future<byte[]>> entry : dexDataFutures.entrySet()) {
-          builder.addDexProgramData(entry.getValue().get(), entry.getKey().getClassDescriptors());
+          VirtualFile virtualFile = entry.getKey();
+          if (virtualFile.getPrimaryClassDescriptor() != null) {
+            builder.addDexProgramData(
+                entry.getValue().get(),
+                virtualFile.getClassDescriptors(),
+                virtualFile.getPrimaryClassDescriptor());
+          } else {
+            builder.addDexProgramData(entry.getValue().get(), virtualFile.getClassDescriptors());
+          }
         }
       } catch (InterruptedException e) {
         throw new RuntimeException("Interrupted while waiting for future.", e);
diff --git a/src/main/java/com/android/tools/r8/dex/FileWriter.java b/src/main/java/com/android/tools/r8/dex/FileWriter.java
index d820747..1e70b9b 100644
--- a/src/main/java/com/android/tools/r8/dex/FileWriter.java
+++ b/src/main/java/com/android/tools/r8/dex/FileWriter.java
@@ -617,7 +617,7 @@
     }
   }
 
-  private void writeEncodedMethods(DexEncodedMethod[] methods) {
+  private void writeEncodedMethods(DexEncodedMethod[] methods, boolean clearBodies) {
     assert isSorted(methods);
     int currentOffset = 0;
     for (DexEncodedMethod method : methods) {
@@ -633,7 +633,9 @@
         dest.putUleb128(mixedSectionOffsets.getOffsetFor(method.getCode().asDexCode()));
         // Writing the methods starts to take up memory so we are going to flush the
         // code objects since they are no longer necessary after this.
-        method.removeCode();
+        if (clearBodies) {
+          method.removeCode();
+        }
       }
     }
   }
@@ -647,8 +649,10 @@
     dest.putUleb128(clazz.virtualMethods().length);
     writeEncodedFields(clazz.staticFields());
     writeEncodedFields(clazz.instanceFields());
-    writeEncodedMethods(clazz.directMethods());
-    writeEncodedMethods(clazz.virtualMethods());
+
+    boolean isSharedSynthetic = clazz.getSynthesizedFrom().size() > 1;
+    writeEncodedMethods(clazz.directMethods(), !isSharedSynthetic);
+    writeEncodedMethods(clazz.virtualMethods(), !isSharedSynthetic);
   }
 
   private void addStaticFieldValues(DexProgramClass clazz) {
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 c40d5a5..32fb175 100644
--- a/src/main/java/com/android/tools/r8/dex/VirtualFile.java
+++ b/src/main/java/com/android/tools/r8/dex/VirtualFile.java
@@ -4,8 +4,8 @@
 package com.android.tools.r8.dex;
 
 import com.android.tools.r8.errors.CompilationError;
-import com.android.tools.r8.errors.InternalCompilerError;
 import com.android.tools.r8.errors.DexOverflowException;
+import com.android.tools.r8.errors.InternalCompilerError;
 import com.android.tools.r8.graph.DexApplication;
 import com.android.tools.r8.graph.DexCallSite;
 import com.android.tools.r8.graph.DexClass;
@@ -76,10 +76,17 @@
   private final VirtualFileIndexedItemCollection indexedItems;
   private final IndexedItemTransaction transaction;
 
+  private final DexProgramClass primaryClass;
+
   private VirtualFile(int id, NamingLens namingLens) {
+    this(id, namingLens, null);
+  }
+
+  private VirtualFile(int id, NamingLens namingLens, DexProgramClass primaryClass) {
     this.id = id;
     this.indexedItems = new VirtualFileIndexedItemCollection(id);
     this.transaction = new IndexedItemTransaction(indexedItems, namingLens);
+    this.primaryClass = primaryClass;
   }
 
   public int getId() {
@@ -95,6 +102,10 @@
     return classDescriptors;
   }
 
+  public String getPrimaryClassDescriptor() {
+    return primaryClass == null ? null : primaryClass.type.descriptor.toString();
+  }
+
   public static String deriveCommonPrefixAndSanityCheck(List<String> fileNames) {
     Iterator<String> nameIterator = fileNames.iterator();
     String first = nameIterator.next();
@@ -221,21 +232,40 @@
         throws ExecutionException, IOException, DexOverflowException;
   }
 
-  public static class FilePerClassDistributor extends Distributor {
+  /**
+   * Distribute each type to its individual virtual except for types synthesized during this
+   * compilation. Synthesized classes are emitted in the individual virtual files
+   * of the input classes they were generated from. Shared synthetic classes
+   * may then be distributed in several individual virtual files.
+   */
+  public static class FilePerInputClassDistributor extends Distributor {
 
-    FilePerClassDistributor(ApplicationWriter writer) {
+    FilePerInputClassDistributor(ApplicationWriter writer) {
       super(writer);
     }
 
     @Override
     public Map<Integer, VirtualFile> run() {
+      HashMap<DexProgramClass, VirtualFile> files = new HashMap<>();
+      Collection<DexProgramClass> synthetics = new ArrayList<>();
       // 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();
+        if (clazz.getSynthesizedFrom().isEmpty()) {
+          VirtualFile file = new VirtualFile(nameToFileMap.size(), writer.namingLens, clazz);
+          nameToFileMap.put(nameToFileMap.size(), file);
+          file.addClass(clazz);
+          files.put(clazz, file);
+        } else {
+          synthetics.add(clazz);
+        }
       }
+      for (DexProgramClass synthetic : synthetics) {
+        for (DexProgramClass inputType : synthetic.getSynthesizedFrom()) {
+          VirtualFile file = files.get(inputType);
+          file.addClass(synthetic);
+        }
+      }
+      files.values().forEach(file -> file.commitTransaction());
       return nameToFileMap;
     }
   }
diff --git a/src/main/java/com/android/tools/r8/graph/DexProgramClass.java b/src/main/java/com/android/tools/r8/graph/DexProgramClass.java
index 1bdc56c..d27a3be 100644
--- a/src/main/java/com/android/tools/r8/graph/DexProgramClass.java
+++ b/src/main/java/com/android/tools/r8/graph/DexProgramClass.java
@@ -7,11 +7,16 @@
 import com.android.tools.r8.dex.IndexedItemCollection;
 import com.android.tools.r8.dex.MixedSectionCollection;
 import java.util.Arrays;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.HashSet;
+import java.util.Set;
 import java.util.function.Supplier;
 
 public class DexProgramClass extends DexClass implements Supplier<DexProgramClass> {
 
   private DexEncodedArray staticValues;
+  private final Collection<DexProgramClass> synthesizedFrom;
 
   public DexProgramClass(DexType type,
       Resource.Kind origin,
@@ -24,9 +29,36 @@
       DexEncodedField[] instanceFields,
       DexEncodedMethod[] directMethods,
       DexEncodedMethod[] virtualMethods) {
+    this(type,
+        origin,
+        accessFlags,
+        superType,
+        interfaces,
+        sourceFile,
+        classAnnotations,
+        staticFields,
+        instanceFields,
+        directMethods,
+        virtualMethods,
+        Collections.emptyList());
+  }
+
+  public DexProgramClass(DexType type,
+      Resource.Kind origin,
+      DexAccessFlags accessFlags,
+      DexType superType,
+      DexTypeList interfaces,
+      DexString sourceFile,
+      DexAnnotationSet classAnnotations,
+      DexEncodedField[] staticFields,
+      DexEncodedField[] instanceFields,
+      DexEncodedMethod[] directMethods,
+      DexEncodedMethod[] virtualMethods,
+      Collection<DexProgramClass> synthesizedDirectlyFrom) {
     super(sourceFile, interfaces, accessFlags, superType, type, staticFields,
         instanceFields, directMethods, virtualMethods, classAnnotations, origin);
     assert classAnnotations != null;
+    this.synthesizedFrom = accumulateSynthesizedFrom(new HashSet<>(), synthesizedDirectlyFrom);
   }
 
   @Override
@@ -54,6 +86,10 @@
     }
   }
 
+  public Collection<DexProgramClass> getSynthesizedFrom() {
+    return synthesizedFrom;
+  }
+
   @Override
   void collectMixedSectionItems(MixedSectionCollection mixedItems) {
     if (hasAnnotations()) {
@@ -129,6 +165,19 @@
     return methods != null && Arrays.stream(methods).anyMatch(DexEncodedMethod::hasAnnotation);
   }
 
+  private static Collection<DexProgramClass> accumulateSynthesizedFrom(
+      Set<DexProgramClass> accumulated,
+      Collection<DexProgramClass> toAccumulate) {
+    for (DexProgramClass dexProgramClass : toAccumulate) {
+      if (dexProgramClass.synthesizedFrom.isEmpty()) {
+        accumulated.add(dexProgramClass);
+      } else {
+        accumulateSynthesizedFrom(accumulated, dexProgramClass.synthesizedFrom);
+      }
+    }
+    return accumulated;
+  }
+
   public void setStaticValues(DexEncodedArray staticValues) {
     this.staticValues = staticValues;
   }
diff --git a/src/main/java/com/android/tools/r8/ir/desugar/InterfaceMethodRewriter.java b/src/main/java/com/android/tools/r8/ir/desugar/InterfaceMethodRewriter.java
index aa93aa8..3d7d254 100644
--- a/src/main/java/com/android/tools/r8/ir/desugar/InterfaceMethodRewriter.java
+++ b/src/main/java/com/android/tools/r8/ir/desugar/InterfaceMethodRewriter.java
@@ -60,7 +60,8 @@
 //       forward the call to an appropriate method in interface companion class.
 //
 public final class InterfaceMethodRewriter {
-  private static final String COMPANION_CLASS_NAME_SUFFIX = "-CC";
+  // public for testing
+  public static final String COMPANION_CLASS_NAME_SUFFIX = "-CC";
   private static final String DEFAULT_METHOD_PREFIX = "$default$";
 
   private final IRConverter converter;
diff --git a/src/main/java/com/android/tools/r8/ir/desugar/InterfaceProcessor.java b/src/main/java/com/android/tools/r8/ir/desugar/InterfaceProcessor.java
index 2d06abe..02d6dc9 100644
--- a/src/main/java/com/android/tools/r8/ir/desugar/InterfaceProcessor.java
+++ b/src/main/java/com/android/tools/r8/ir/desugar/InterfaceProcessor.java
@@ -17,6 +17,7 @@
 import com.android.tools.r8.graph.DexType;
 import com.android.tools.r8.graph.DexTypeList;
 import java.util.ArrayList;
+import java.util.Collections;
 import java.util.IdentityHashMap;
 import java.util.List;
 import java.util.Map;
@@ -135,7 +136,8 @@
         DexEncodedField.EMPTY_ARRAY,
         DexEncodedField.EMPTY_ARRAY,
         companionMethods.toArray(new DexEncodedMethod[companionMethods.size()]),
-        DexEncodedMethod.EMPTY_ARRAY
+        DexEncodedMethod.EMPTY_ARRAY,
+        Collections.singletonList(iface)
     );
     companionClasses.put(iface, companionClass);
   }
diff --git a/src/main/java/com/android/tools/r8/ir/desugar/LambdaClass.java b/src/main/java/com/android/tools/r8/ir/desugar/LambdaClass.java
index f03a619..0fe0f99 100644
--- a/src/main/java/com/android/tools/r8/ir/desugar/LambdaClass.java
+++ b/src/main/java/com/android/tools/r8/ir/desugar/LambdaClass.java
@@ -27,6 +27,8 @@
 import com.android.tools.r8.graph.DexValue.DexValueNull;
 import com.android.tools.r8.ir.code.Invoke;
 import com.android.tools.r8.ir.synthetic.SynthesizedCode;
+import java.util.ArrayList;
+import java.util.Collection;
 import java.util.List;
 import java.util.concurrent.atomic.AtomicBoolean;
 
@@ -58,6 +60,7 @@
   final DexField instanceField;
   final Target target;
   final AtomicBoolean addToMainDexList = new AtomicBoolean(false);
+  private Collection<DexProgramClass> synthesizedFrom = new ArrayList<DexProgramClass>(1);
 
   LambdaClass(LambdaRewriter rewriter, DexType accessedFrom,
       DexType lambdaClassType, LambdaDescriptor descriptor) {
@@ -125,7 +128,8 @@
         synthesizeStaticFields(),
         synthesizeInstanceFields(),
         synthesizeDirectMethods(),
-        synthesizeVirtualMethods()
+        synthesizeVirtualMethods(),
+        synthesizedFrom
     );
   }
 
@@ -138,6 +142,11 @@
     return descriptor.isStateless();
   }
 
+  synchronized void addSynthesizedFrom(DexProgramClass synthesizedFrom) {
+    assert synthesizedFrom != null;
+    this.synthesizedFrom.add(synthesizedFrom);
+  }
+
   // Synthesize virtual methods.
   private DexEncodedMethod[] synthesizeVirtualMethods() {
     DexEncodedMethod[] methods = new DexEncodedMethod[1 + descriptor.bridges.size()];
diff --git a/src/main/java/com/android/tools/r8/ir/desugar/LambdaRewriter.java b/src/main/java/com/android/tools/r8/ir/desugar/LambdaRewriter.java
index 86ad391..c31675f 100644
--- a/src/main/java/com/android/tools/r8/ir/desugar/LambdaRewriter.java
+++ b/src/main/java/com/android/tools/r8/ir/desugar/LambdaRewriter.java
@@ -54,7 +54,8 @@
   private static final String METAFACTORY_ALT_METHOD_NAME = "altMetafactory";
   private static final String DESERIALIZE_LAMBDA_METHOD_NAME = "$deserializeLambda$";
 
-  static final String LAMBDA_CLASS_NAME_PREFIX = "-$$Lambda$";
+  // public for testing
+  public static final String LAMBDA_CLASS_NAME_PREFIX = "-$$Lambda$";
   static final String EXPECTED_LAMBDA_METHOD_PREFIX = "lambda$";
   static final String LAMBDA_INSTANCE_FIELD_NAME = "INSTANCE";
 
@@ -238,6 +239,7 @@
       lambdaClass = putIfAbsent(knownLambdaClasses, lambdaClassType,
           new LambdaClass(this, accessedFrom, lambdaClassType, descriptor));
     }
+    lambdaClass.addSynthesizedFrom(appInfo.definitionFor(accessedFrom).asProgramClass());
     if (isInMainDexList(accessedFrom)) {
       lambdaClass.addToMainDexList.set(true);
     }
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 54d10a0..9d31763 100644
--- a/src/main/java/com/android/tools/r8/utils/AndroidApp.java
+++ b/src/main/java/com/android/tools/r8/utils/AndroidApp.java
@@ -14,8 +14,10 @@
 import com.android.tools.r8.dex.VDexFile;
 import com.android.tools.r8.dex.VDexFileReader;
 import com.android.tools.r8.errors.CompilationError;
+import com.android.tools.r8.errors.Unreachable;
 import com.android.tools.r8.shaking.FilteredClassPath;
 import com.google.common.collect.ImmutableList;
+import com.google.common.collect.ImmutableMap;
 import com.google.common.io.ByteStreams;
 import com.google.common.io.Closer;
 import java.io.ByteArrayOutputStream;
@@ -34,7 +36,9 @@
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collection;
+import java.util.HashMap;
 import java.util.List;
+import java.util.Map;
 import java.util.Set;
 import java.util.stream.Collectors;
 import java.util.stream.Stream;
@@ -51,6 +55,7 @@
   public static final String DEFAULT_PROGUARD_MAP_FILE = "proguard.map";
 
   private final ImmutableList<Resource> programResources;
+  private final ImmutableMap<Resource, String> programResourcesMainDescriptor;
   private final ImmutableList<ClassFileResourceProvider> classpathResourceProviders;
   private final ImmutableList<ClassFileResourceProvider> libraryResourceProviders;
 
@@ -66,6 +71,7 @@
   // See factory methods and AndroidApp.Builder below.
   private AndroidApp(
       ImmutableList<Resource> programResources,
+      ImmutableMap<Resource, String> programResourcesMainDescriptor,
       ImmutableList<ProgramFileArchiveReader> programFileArchiveReaders,
       ImmutableList<ClassFileResourceProvider> classpathResourceProviders,
       ImmutableList<ClassFileResourceProvider> libraryResourceProviders,
@@ -77,6 +83,7 @@
       List<String> mainDexClasses,
       Resource mainDexListOutput) {
     this.programResources = programResources;
+    this.programResourcesMainDescriptor = programResourcesMainDescriptor;
     this.programFileArchiveReaders = programFileArchiveReaders;
     this.classpathResourceProviders = classpathResourceProviders;
     this.libraryResourceProviders = libraryResourceProviders;
@@ -331,7 +338,7 @@
     try (Closer closer = Closer.create()) {
       List<Resource> dexProgramSources = getDexProgramResources();
       for (int i = 0; i < dexProgramSources.size(); i++) {
-        Path filePath = directory.resolve(outputMode.getOutputPath(dexProgramSources.get(i), i));
+        Path filePath = directory.resolve(getOutputPath(outputMode, dexProgramSources.get(i), i));
         if (!Files.exists(filePath.getParent())) {
           Files.createDirectories(filePath.getParent());
         }
@@ -340,6 +347,19 @@
     }
   }
 
+  private String getOutputPath(OutputMode outputMode, Resource resource, int index) {
+    switch (outputMode) {
+      case Indexed:
+        return index == 0 ? "classes.dex" : ("classes" + (index + 1) + ".dex");
+      case FilePerInputClass:
+        String classDescriptor = programResourcesMainDescriptor.get(resource);
+        assert classDescriptor!= null && DescriptorUtils.isClassDescriptor(classDescriptor);
+        return classDescriptor.substring(1, classDescriptor.length() - 1) + ".dex";
+      default:
+        throw new Unreachable("Unknown output mode: " + outputMode);
+    }
+  }
+
   private static boolean isClassesDexFile(Path file) {
     String name = file.getFileName().toString().toLowerCase();
     if (!name.startsWith("classes") || !name.endsWith(".dex")) {
@@ -389,7 +409,7 @@
       try (ZipOutputStream out = new ZipOutputStream(Files.newOutputStream(archive, options))) {
         List<Resource> dexProgramSources = getDexProgramResources();
         for (int i = 0; i < dexProgramSources.size(); i++) {
-          ZipEntry zipEntry = new ZipEntry(outputMode.getOutputPath(dexProgramSources.get(i), i));
+          ZipEntry zipEntry = new ZipEntry(getOutputPath(outputMode, dexProgramSources.get(i), i));
           byte[] bytes =
               ByteStreams.toByteArray(closer.register(dexProgramSources.get(i).getStream()));
           zipEntry.setSize(bytes.length);
@@ -426,12 +446,17 @@
     out.write(ByteStreams.toByteArray(input));
   }
 
+  String getPrimaryClassDescriptor(Resource resource) {
+    return programResourcesMainDescriptor.get(resource);
+  }
+
   /**
    * Builder interface for constructing an AndroidApp.
    */
   public static class Builder {
 
     private final List<Resource> programResources = new ArrayList<>();
+    private final Map<Resource, String> programResourcesMainDescriptor = new HashMap<>();
     private final List<ProgramFileArchiveReader> programFileArchiveReaders = new ArrayList<>();
     private final List<ClassFileResourceProvider> classpathResourceProviders = new ArrayList<>();
     private final List<ClassFileResourceProvider> libraryResourceProviders = new ArrayList<>();
@@ -564,6 +589,19 @@
     }
 
     /**
+     * Add dex program-data with class descriptor and primary class.
+     */
+    public Builder addDexProgramData(
+        byte[] data,
+        Set<String> classDescriptors,
+        String primaryClassDescriptor) {
+      Resource resource = Resource.fromBytes(Resource.Kind.DEX, data, classDescriptors);
+      programResources.add(resource);
+      programResourcesMainDescriptor.put(resource, primaryClassDescriptor);
+      return this;
+    }
+
+    /**
      * Add dex program-data.
      */
     public Builder addDexProgramData(byte[]... data) {
@@ -727,6 +765,7 @@
     public AndroidApp build() {
       return new AndroidApp(
           ImmutableList.copyOf(programResources),
+          ImmutableMap.copyOf(programResourcesMainDescriptor),
           ImmutableList.copyOf(programFileArchiveReaders),
           ImmutableList.copyOf(classpathResourceProviders),
           ImmutableList.copyOf(libraryResourceProviders),
diff --git a/src/main/java/com/android/tools/r8/utils/OutputMode.java b/src/main/java/com/android/tools/r8/utils/OutputMode.java
index 1bdf501..4520cd6 100644
--- a/src/main/java/com/android/tools/r8/utils/OutputMode.java
+++ b/src/main/java/com/android/tools/r8/utils/OutputMode.java
@@ -3,28 +3,8 @@
 // BSD-style license that can be found in the LICENSE file.
 package com.android.tools.r8.utils;
 
-import com.android.tools.r8.Resource;
-import java.util.Set;
-
 /** Defines way the output is formed. */
 public enum OutputMode {
-  Indexed {
-    @Override
-    String getOutputPath(Resource resource, int index) {
-      return index == 0 ? "classes.dex" : ("classes" + (index + 1) + ".dex");
-    }
-  },
-  FilePerClass {
-    @Override
-    String getOutputPath(Resource resource, int index) {
-      Set<String> classDescriptors = resource.getClassDescriptors();
-      assert classDescriptors != null;
-      assert classDescriptors.size() == 1;
-      String classDescriptor = classDescriptors.iterator().next();
-      assert DescriptorUtils.isClassDescriptor(classDescriptor);
-      return classDescriptor.substring(1, classDescriptor.length() - 1) + ".dex";
-    }
-  };
-
-  abstract String getOutputPath(Resource resource, int index);
+  Indexed,
+  FilePerInputClass;
 }
diff --git a/src/test/java/com/android/tools/r8/D8IncrementalRunExamplesAndroidOTest.java b/src/test/java/com/android/tools/r8/D8IncrementalRunExamplesAndroidOTest.java
index 6461a57..711453b 100644
--- a/src/test/java/com/android/tools/r8/D8IncrementalRunExamplesAndroidOTest.java
+++ b/src/test/java/com/android/tools/r8/D8IncrementalRunExamplesAndroidOTest.java
@@ -11,9 +11,13 @@
 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.ir.desugar.InterfaceMethodRewriter;
+import com.android.tools.r8.ir.desugar.LambdaRewriter;
 import com.android.tools.r8.utils.AndroidApp;
+import com.android.tools.r8.utils.DescriptorUtils;
 import com.android.tools.r8.utils.OffOrAuto;
 import com.android.tools.r8.utils.OutputMode;
+import com.android.tools.r8.utils.UtilsHelper;
 import com.beust.jcommander.internal.Lists;
 import com.google.common.io.Closer;
 import java.io.ByteArrayOutputStream;
@@ -77,13 +81,19 @@
       TreeMap<String, Resource> fileToResource = new TreeMap<>();
       List<String> classFiles = collectClassFiles(testJarFile);
       AndroidApp app = compileClassFiles(
-          testJarFile, classFiles, output, OutputMode.FilePerClass);
+          testJarFile, classFiles, output, OutputMode.FilePerInputClass);
       for (Resource resource : app.getDexProgramResources()) {
         Set<String> descriptors = resource.getClassDescriptors();
-        Assert.assertNotNull(descriptors);
-        Assert.assertEquals(1, descriptors.size());
-        String classDescriptor = descriptors.iterator().next();
-        classDescriptor = classDescriptor.substring(1, classDescriptor.length() - 1);
+        String mainClassDescriptor = UtilsHelper.getMainClassDescriptor(app, resource);
+        for (String descriptor : descriptors) {
+          // classes are either lambda classes used by the main class, companion classes of the main
+          // interface or the main class/interface
+          Assert.assertTrue(descriptor.contains(LambdaRewriter.LAMBDA_CLASS_NAME_PREFIX)
+              || descriptor.endsWith(InterfaceMethodRewriter.COMPANION_CLASS_NAME_SUFFIX + ";")
+              || descriptor.equals(mainClassDescriptor));
+        }
+        String classDescriptor =
+            DescriptorUtils.getClassBinaryNameFromDescriptor(mainClassDescriptor);
         String classFilePath = classDescriptor + ".class";
         if (File.separatorChar != '/') {
           classFilePath = classFilePath.replace('/', File.separatorChar);
diff --git a/src/test/java/com/android/tools/r8/maindexlist/MainDexTracingTest.java b/src/test/java/com/android/tools/r8/maindexlist/MainDexTracingTest.java
index ba5092f..cc56417 100644
--- a/src/test/java/com/android/tools/r8/maindexlist/MainDexTracingTest.java
+++ b/src/test/java/com/android/tools/r8/maindexlist/MainDexTracingTest.java
@@ -15,6 +15,7 @@
 import com.android.tools.r8.ToolHelper;
 import com.android.tools.r8.graph.DexClass;
 import com.android.tools.r8.graph.DexType;
+import com.android.tools.r8.ir.desugar.LambdaRewriter;
 import com.android.tools.r8.utils.DescriptorUtils;
 import com.android.tools.r8.utils.InternalOptions;
 import java.nio.charset.StandardCharsets;
@@ -179,7 +180,7 @@
   }
 
   private boolean isLambda(String mainDexEntry) {
-    return mainDexEntry.contains("-$$Lambda$");
+    return mainDexEntry.contains(LambdaRewriter.LAMBDA_CLASS_NAME_PREFIX);
   }
 
   private String mainDexStringToDescriptor(String mainDexString) {
diff --git a/src/test/java/com/android/tools/r8/utils/OutputModeTest.java b/src/test/java/com/android/tools/r8/utils/OutputModeTest.java
deleted file mode 100644
index 5929b60..0000000
--- a/src/test/java/com/android/tools/r8/utils/OutputModeTest.java
+++ /dev/null
@@ -1,34 +0,0 @@
-// 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 static org.junit.Assert.assertEquals;
-
-import com.android.tools.r8.Resource;
-import java.util.Collections;
-import org.junit.Test;
-
-public class OutputModeTest {
-  @Test
-  public void testIndexedFileName() {
-    assertEquals("classes.dex", OutputMode.Indexed.getOutputPath(null, 0));
-    assertEquals("classes2.dex", OutputMode.Indexed.getOutputPath(null, 1));
-  }
-
-  @Test
-  public void testFilePerClass() {
-    Resource test =
-        Resource.fromBytes(Resource.Kind.CLASSFILE, new byte[]{}, Collections.singleton("LTest;"));
-    assertEquals("Test.dex", OutputMode.FilePerClass.getOutputPath(test, 0));
-    Resource comTest =
-        Resource.fromBytes(
-            Resource.Kind.CLASSFILE, new byte[]{}, Collections.singleton("Lcom/Test;"));
-    assertEquals("com/Test.dex", OutputMode.FilePerClass.getOutputPath(comTest, 0));
-    Resource comExampleTest =
-        Resource.fromBytes(
-            Resource.Kind.CLASSFILE, new byte[]{}, Collections.singleton("Lcom/example/Test;"));
-    assertEquals("com/example/Test.dex", OutputMode.FilePerClass.getOutputPath(comExampleTest, 0));
-    assertEquals("com/example/Test.dex", OutputMode.FilePerClass.getOutputPath(comExampleTest, 1));
-  }
-}