diff --git a/src/test/java/com/android/tools/r8/kotlin/metadata/MetadataRenameInExtensionTest.java b/src/test/java/com/android/tools/r8/kotlin/metadata/MetadataRenameInExtensionFunctionTest.java
similarity index 85%
rename from src/test/java/com/android/tools/r8/kotlin/metadata/MetadataRenameInExtensionTest.java
rename to src/test/java/com/android/tools/r8/kotlin/metadata/MetadataRenameInExtensionFunctionTest.java
index 6f9dd7f..8e1e6b7 100644
--- a/src/test/java/com/android/tools/r8/kotlin/metadata/MetadataRenameInExtensionTest.java
+++ b/src/test/java/com/android/tools/r8/kotlin/metadata/MetadataRenameInExtensionFunctionTest.java
@@ -30,7 +30,7 @@
 import org.junit.runners.Parameterized;
 
 @RunWith(Parameterized.class)
-public class MetadataRenameInExtensionTest extends KotlinMetadataTestBase {
+public class MetadataRenameInExtensionFunctionTest extends KotlinMetadataTestBase {
 
   private final TestParameters parameters;
 
@@ -40,7 +40,7 @@
         getTestParameters().withCfRuntimes().build(), KotlinTargetVersion.values());
   }
 
-  public MetadataRenameInExtensionTest(
+  public MetadataRenameInExtensionFunctionTest(
       TestParameters parameters, KotlinTargetVersion targetVersion) {
     super(targetVersion);
     this.parameters = parameters;
@@ -50,7 +50,7 @@
 
   @BeforeClass
   public static void createLibJar() throws Exception {
-    String extLibFolder = PKG_PREFIX + "/extension_lib";
+    String extLibFolder = PKG_PREFIX + "/extension_function_lib";
     extLibJar =
         kotlinc(KOTLINC, KotlinTargetVersion.JAVA_8)
             .addSourceFiles(getKotlinFileInTest(extLibFolder, "B"))
@@ -58,23 +58,23 @@
   }
 
   @Test
-  public void testMetadataInExtension_merged() throws Exception {
+  public void testMetadataInExtensionFunction_merged() throws Exception {
     R8TestCompileResult compileResult =
         testForR8(parameters.getBackend())
             .addProgramFiles(extLibJar)
             // Keep the B class and its interface (which has the doStuff method).
             .addKeepRules("-keep class **.B")
             .addKeepRules("-keep class **.I { <methods>; }")
-            // Keep the BKt extension method which requires metadata
+            // Keep the BKt extension function which requires metadata
             // to be called with Kotlin syntax from other kotlin code.
             .addKeepRules("-keep class **.BKt { <methods>; }")
             .addKeepAttributes(ProguardKeepAttributes.RUNTIME_VISIBLE_ANNOTATIONS)
             .addOptionsModification(InternalOptions::enableKotlinMetadataRewriting)
             .compile();
     String pkg = getClass().getPackage().getName();
-    final String superClassName = pkg + ".extension_lib.Super";
-    final String bClassName = pkg + ".extension_lib.B";
-    final String bKtClassName = pkg + ".extension_lib.BKt";
+    final String superClassName = pkg + ".extension_function_lib.Super";
+    final String bClassName = pkg + ".extension_function_lib.B";
+    final String bKtClassName = pkg + ".extension_function_lib.BKt";
     compileResult.inspect(inspector -> {
       assertThat(inspector.clazz(superClassName), not(isPresent()));
 
@@ -101,7 +101,7 @@
 
     Path libJar = compileResult.writeToZip();
 
-    String appFolder = PKG_PREFIX + "/extension_app";
+    String appFolder = PKG_PREFIX + "/extension_function_app";
     Path output =
         kotlinc(parameters.getRuntime().asCf(), KOTLINC, KotlinTargetVersion.JAVA_8)
             .addClasspathFiles(libJar)
@@ -112,12 +112,12 @@
     testForJvm()
         .addRunClasspathFiles(ToolHelper.getKotlinStdlibJar(), libJar)
         .addClasspath(output)
-        .run(parameters.getRuntime(), pkg + ".extension_app.MainKt")
+        .run(parameters.getRuntime(), pkg + ".extension_function_app.MainKt")
         .assertSuccessWithOutputLines("do stuff", "do stuff");
   }
 
   @Test
-  public void testMetadataInExtension_renamed() throws Exception {
+  public void testMetadataInExtensionFunction_renamed() throws Exception {
     R8TestCompileResult compileResult =
         testForR8(parameters.getBackend())
             .addProgramFiles(extLibJar)
@@ -126,16 +126,16 @@
             .addKeepRules("-keep class **.I { <methods>; }")
             // Keep Super, but allow minification.
             .addKeepRules("-keep,allowobfuscation class **.Super")
-            // Keep the BKt extension method which requires metadata
+            // Keep the BKt extension function which requires metadata
             // to be called with Kotlin syntax from other kotlin code.
             .addKeepRules("-keep class **.BKt { <methods>; }")
             .addKeepAttributes(ProguardKeepAttributes.RUNTIME_VISIBLE_ANNOTATIONS)
             .addOptionsModification(InternalOptions::enableKotlinMetadataRewriting)
             .compile();
     String pkg = getClass().getPackage().getName();
-    final String superClassName = pkg + ".extension_lib.Super";
-    final String bClassName = pkg + ".extension_lib.B";
-    final String bKtClassName = pkg + ".extension_lib.BKt";
+    final String superClassName = pkg + ".extension_function_lib.Super";
+    final String bClassName = pkg + ".extension_function_lib.B";
+    final String bKtClassName = pkg + ".extension_function_lib.BKt";
     compileResult.inspect(inspector -> {
       ClassSubject sup = inspector.clazz(superClassName);
       assertThat(sup, isPresent());
@@ -166,7 +166,7 @@
 
     Path libJar = compileResult.writeToZip();
 
-    String appFolder = PKG_PREFIX + "/extension_app";
+    String appFolder = PKG_PREFIX + "/extension_function_app";
     Path output =
         kotlinc(parameters.getRuntime().asCf(), KOTLINC, KotlinTargetVersion.JAVA_8)
             .addClasspathFiles(libJar)
@@ -177,7 +177,7 @@
     testForJvm()
         .addRunClasspathFiles(ToolHelper.getKotlinStdlibJar(), libJar)
         .addClasspath(output)
-        .run(parameters.getRuntime(), pkg + ".extension_app.MainKt")
+        .run(parameters.getRuntime(), pkg + ".extension_function_app.MainKt")
         .assertSuccessWithOutputLines("do stuff", "do stuff");
   }
 }
diff --git a/src/test/java/com/android/tools/r8/kotlin/metadata/MetadataRenameInExtensionTest.java b/src/test/java/com/android/tools/r8/kotlin/metadata/MetadataRenameInExtensionPropertyTest.java
similarity index 74%
copy from src/test/java/com/android/tools/r8/kotlin/metadata/MetadataRenameInExtensionTest.java
copy to src/test/java/com/android/tools/r8/kotlin/metadata/MetadataRenameInExtensionPropertyTest.java
index 6f9dd7f..0b327c9 100644
--- a/src/test/java/com/android/tools/r8/kotlin/metadata/MetadataRenameInExtensionTest.java
+++ b/src/test/java/com/android/tools/r8/kotlin/metadata/MetadataRenameInExtensionPropertyTest.java
@@ -1,25 +1,25 @@
-// Copyright (c) 2019, the R8 project authors. Please see the AUTHORS file
+// Copyright (c) 2020, 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.kotlin.metadata;
 
 import static com.android.tools.r8.KotlinCompilerTool.KOTLINC;
-import static com.android.tools.r8.utils.codeinspector.Matchers.isExtension;
 import static com.android.tools.r8.utils.codeinspector.Matchers.isPresent;
 import static com.android.tools.r8.utils.codeinspector.Matchers.isRenamed;
+import static org.hamcrest.CoreMatchers.containsString;
 import static org.hamcrest.CoreMatchers.not;
 import static org.hamcrest.MatcherAssert.assertThat;
+import static org.junit.Assert.assertNotEquals;
 import static org.junit.Assert.assertTrue;
 
 import com.android.tools.r8.R8TestCompileResult;
 import com.android.tools.r8.TestParameters;
-import com.android.tools.r8.ToolHelper;
 import com.android.tools.r8.ToolHelper.KotlinTargetVersion;
+import com.android.tools.r8.ToolHelper.ProcessResult;
 import com.android.tools.r8.shaking.ProguardKeepAttributes;
 import com.android.tools.r8.utils.InternalOptions;
 import com.android.tools.r8.utils.codeinspector.ClassSubject;
 import com.android.tools.r8.utils.codeinspector.KmClassSubject;
-import com.android.tools.r8.utils.codeinspector.KmFunctionSubject;
 import com.android.tools.r8.utils.codeinspector.KmPackageSubject;
 import java.nio.file.Path;
 import java.util.Collection;
@@ -30,7 +30,7 @@
 import org.junit.runners.Parameterized;
 
 @RunWith(Parameterized.class)
-public class MetadataRenameInExtensionTest extends KotlinMetadataTestBase {
+public class MetadataRenameInExtensionPropertyTest extends KotlinMetadataTestBase {
 
   private final TestParameters parameters;
 
@@ -40,7 +40,7 @@
         getTestParameters().withCfRuntimes().build(), KotlinTargetVersion.values());
   }
 
-  public MetadataRenameInExtensionTest(
+  public MetadataRenameInExtensionPropertyTest(
       TestParameters parameters, KotlinTargetVersion targetVersion) {
     super(targetVersion);
     this.parameters = parameters;
@@ -50,7 +50,7 @@
 
   @BeforeClass
   public static void createLibJar() throws Exception {
-    String extLibFolder = PKG_PREFIX + "/extension_lib";
+    String extLibFolder = PKG_PREFIX + "/extension_property_lib";
     extLibJar =
         kotlinc(KOTLINC, KotlinTargetVersion.JAVA_8)
             .addSourceFiles(getKotlinFileInTest(extLibFolder, "B"))
@@ -58,23 +58,23 @@
   }
 
   @Test
-  public void testMetadataInExtension_merged() throws Exception {
+  public void testMetadataInExtensionProperty_merged() throws Exception {
     R8TestCompileResult compileResult =
         testForR8(parameters.getBackend())
             .addProgramFiles(extLibJar)
             // Keep the B class and its interface (which has the doStuff method).
             .addKeepRules("-keep class **.B")
             .addKeepRules("-keep class **.I { <methods>; }")
-            // Keep the BKt extension method which requires metadata
+            // Keep the BKt extension property which requires metadata
             // to be called with Kotlin syntax from other kotlin code.
             .addKeepRules("-keep class **.BKt { <methods>; }")
             .addKeepAttributes(ProguardKeepAttributes.RUNTIME_VISIBLE_ANNOTATIONS)
             .addOptionsModification(InternalOptions::enableKotlinMetadataRewriting)
             .compile();
     String pkg = getClass().getPackage().getName();
-    final String superClassName = pkg + ".extension_lib.Super";
-    final String bClassName = pkg + ".extension_lib.B";
-    final String bKtClassName = pkg + ".extension_lib.BKt";
+    final String superClassName = pkg + ".extension_property_lib.Super";
+    final String bClassName = pkg + ".extension_property_lib.B";
+    final String bKtClassName = pkg + ".extension_property_lib.BKt";
     compileResult.inspect(inspector -> {
       assertThat(inspector.clazz(superClassName), not(isPresent()));
 
@@ -95,29 +95,25 @@
       KmPackageSubject kmPackage = bKt.getKmPackage();
       assertThat(kmPackage, isPresent());
 
-      KmFunctionSubject kmFunction = kmPackage.kmFunctionExtensionWithUniqueName("extension");
-      assertThat(kmFunction, isExtension());
+      // TODO(b/70169921): test property details.
     });
 
     Path libJar = compileResult.writeToZip();
 
-    String appFolder = PKG_PREFIX + "/extension_app";
-    Path output =
+    String appFolder = PKG_PREFIX + "/extension_property_app";
+    ProcessResult processResult =
         kotlinc(parameters.getRuntime().asCf(), KOTLINC, KotlinTargetVersion.JAVA_8)
             .addClasspathFiles(libJar)
             .addSourceFiles(getKotlinFileInTest(appFolder, "main"))
             .setOutputPath(temp.newFolder().toPath())
-            .compile();
-
-    testForJvm()
-        .addRunClasspathFiles(ToolHelper.getKotlinStdlibJar(), libJar)
-        .addClasspath(output)
-        .run(parameters.getRuntime(), pkg + ".extension_app.MainKt")
-        .assertSuccessWithOutputLines("do stuff", "do stuff");
+            .compileRaw();
+    // TODO(b/70169921): should be able to compile!
+    assertNotEquals(0, processResult.exitCode);
+    assertThat(processResult.stderr, containsString("unresolved reference: doStuff"));
   }
 
   @Test
-  public void testMetadataInExtension_renamed() throws Exception {
+  public void testMetadataInExtensionProperty_renamed() throws Exception {
     R8TestCompileResult compileResult =
         testForR8(parameters.getBackend())
             .addProgramFiles(extLibJar)
@@ -126,16 +122,16 @@
             .addKeepRules("-keep class **.I { <methods>; }")
             // Keep Super, but allow minification.
             .addKeepRules("-keep,allowobfuscation class **.Super")
-            // Keep the BKt extension method which requires metadata
+            // Keep the BKt extension property which requires metadata
             // to be called with Kotlin syntax from other kotlin code.
             .addKeepRules("-keep class **.BKt { <methods>; }")
             .addKeepAttributes(ProguardKeepAttributes.RUNTIME_VISIBLE_ANNOTATIONS)
             .addOptionsModification(InternalOptions::enableKotlinMetadataRewriting)
             .compile();
     String pkg = getClass().getPackage().getName();
-    final String superClassName = pkg + ".extension_lib.Super";
-    final String bClassName = pkg + ".extension_lib.B";
-    final String bKtClassName = pkg + ".extension_lib.BKt";
+    final String superClassName = pkg + ".extension_property_lib.Super";
+    final String bClassName = pkg + ".extension_property_lib.B";
+    final String bKtClassName = pkg + ".extension_property_lib.BKt";
     compileResult.inspect(inspector -> {
       ClassSubject sup = inspector.clazz(superClassName);
       assertThat(sup, isPresent());
@@ -160,24 +156,20 @@
       KmPackageSubject kmPackage = bKt.getKmPackage();
       assertThat(kmPackage, isPresent());
 
-      KmFunctionSubject kmFunction = kmPackage.kmFunctionExtensionWithUniqueName("extension");
-      assertThat(kmFunction, isExtension());
+      // TODO(b/70169921): test property details.
     });
 
     Path libJar = compileResult.writeToZip();
 
-    String appFolder = PKG_PREFIX + "/extension_app";
-    Path output =
+    String appFolder = PKG_PREFIX + "/extension_property_app";
+    ProcessResult processResult =
         kotlinc(parameters.getRuntime().asCf(), KOTLINC, KotlinTargetVersion.JAVA_8)
             .addClasspathFiles(libJar)
             .addSourceFiles(getKotlinFileInTest(appFolder, "main"))
             .setOutputPath(temp.newFolder().toPath())
-            .compile();
-
-    testForJvm()
-        .addRunClasspathFiles(ToolHelper.getKotlinStdlibJar(), libJar)
-        .addClasspath(output)
-        .run(parameters.getRuntime(), pkg + ".extension_app.MainKt")
-        .assertSuccessWithOutputLines("do stuff", "do stuff");
+            .compileRaw();
+    // TODO(b/70169921): should be able to compile!
+    assertNotEquals(0, processResult.exitCode);
+    assertThat(processResult.stderr, containsString("unresolved reference: doStuff"));
   }
-}
+}
\ No newline at end of file
diff --git a/src/test/java/com/android/tools/r8/kotlin/metadata/extension_app/main.kt b/src/test/java/com/android/tools/r8/kotlin/metadata/extension_app/main.kt
deleted file mode 100644
index 246d3fe..0000000
--- a/src/test/java/com/android/tools/r8/kotlin/metadata/extension_app/main.kt
+++ /dev/null
@@ -1,12 +0,0 @@
-// Copyright (c) 2019, 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.kotlin.metadata.extension_app
-
-import com.android.tools.r8.kotlin.metadata.extension_lib.B
-import com.android.tools.r8.kotlin.metadata.extension_lib.extension
-
-fun main() {
-  B().doStuff()
-  B().extension()
-}
diff --git a/src/test/java/com/android/tools/r8/kotlin/metadata/extension_function_app/main.kt b/src/test/java/com/android/tools/r8/kotlin/metadata/extension_function_app/main.kt
new file mode 100644
index 0000000..2196586
--- /dev/null
+++ b/src/test/java/com/android/tools/r8/kotlin/metadata/extension_function_app/main.kt
@@ -0,0 +1,12 @@
+// Copyright (c) 2019, 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.kotlin.metadata.extension_function_app
+
+import com.android.tools.r8.kotlin.metadata.extension_function_lib.B
+import com.android.tools.r8.kotlin.metadata.extension_function_lib.extension
+
+fun main() {
+  B().doStuff()
+  B().extension()
+}
diff --git a/src/test/java/com/android/tools/r8/kotlin/metadata/extension_lib/B.kt b/src/test/java/com/android/tools/r8/kotlin/metadata/extension_function_lib/B.kt
similarity index 84%
rename from src/test/java/com/android/tools/r8/kotlin/metadata/extension_lib/B.kt
rename to src/test/java/com/android/tools/r8/kotlin/metadata/extension_function_lib/B.kt
index df51d42..84c759a 100644
--- a/src/test/java/com/android/tools/r8/kotlin/metadata/extension_lib/B.kt
+++ b/src/test/java/com/android/tools/r8/kotlin/metadata/extension_function_lib/B.kt
@@ -1,7 +1,7 @@
 // Copyright (c) 2019, 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.kotlin.metadata.extension_lib
+package com.android.tools.r8.kotlin.metadata.extension_function_lib
 
 interface I {
   fun doStuff()
diff --git a/src/test/java/com/android/tools/r8/kotlin/metadata/extension_property_app/main.kt b/src/test/java/com/android/tools/r8/kotlin/metadata/extension_property_app/main.kt
new file mode 100644
index 0000000..320bad9
--- /dev/null
+++ b/src/test/java/com/android/tools/r8/kotlin/metadata/extension_property_app/main.kt
@@ -0,0 +1,13 @@
+// Copyright (c) 2020, 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.kotlin.metadata.extension_property_app
+
+import com.android.tools.r8.kotlin.metadata.extension_property_lib.B
+import com.android.tools.r8.kotlin.metadata.extension_property_lib.asI
+
+fun main() {
+  val b = B()
+  b.doStuff()
+  b.asI.doStuff()
+}
\ No newline at end of file
diff --git a/src/test/java/com/android/tools/r8/kotlin/metadata/extension_lib/B.kt b/src/test/java/com/android/tools/r8/kotlin/metadata/extension_property_lib/B.kt
similarity index 63%
copy from src/test/java/com/android/tools/r8/kotlin/metadata/extension_lib/B.kt
copy to src/test/java/com/android/tools/r8/kotlin/metadata/extension_property_lib/B.kt
index df51d42..4be711f 100644
--- a/src/test/java/com/android/tools/r8/kotlin/metadata/extension_lib/B.kt
+++ b/src/test/java/com/android/tools/r8/kotlin/metadata/extension_property_lib/B.kt
@@ -1,7 +1,7 @@
-// Copyright (c) 2019, the R8 project authors. Please see the AUTHORS file
+// Copyright (c) 2020, 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.kotlin.metadata.extension_lib
+package com.android.tools.r8.kotlin.metadata.extension_property_lib
 
 interface I {
   fun doStuff()
@@ -15,6 +15,5 @@
 
 class B : Super()
 
-fun B.extension() {
-  doStuff()
-}
\ No newline at end of file
+val B.asI : I
+  get() = this