diff --git a/src/main/java/com/android/tools/r8/shaking/RootSetBuilder.java b/src/main/java/com/android/tools/r8/shaking/RootSetBuilder.java
index 1f588d8..5b3038f 100644
--- a/src/main/java/com/android/tools/r8/shaking/RootSetBuilder.java
+++ b/src/main/java/com/android/tools/r8/shaking/RootSetBuilder.java
@@ -1049,7 +1049,6 @@
     dependentNoShrinking
         .computeIfAbsent(item.toReference(), x -> new MutableItemsWithRules())
         .addClassWithRule(type, context);
-    // TODO(b/171289133): Test and implement allowshrinking and use of -includedescriptorclasses
     // Unconditionally add to no-obfuscation, as that is only checked for surviving items.
     if (appView.options().isMinificationEnabled()) {
       noObfuscation.add(type);
diff --git a/src/test/java/com/android/tools/r8/shaking/allowshrinking/KeepAllowShrinkingIncludeDescriptorClassesCompatibilityTest.java b/src/test/java/com/android/tools/r8/shaking/allowshrinking/KeepAllowShrinkingIncludeDescriptorClassesCompatibilityTest.java
new file mode 100644
index 0000000..44abb34
--- /dev/null
+++ b/src/test/java/com/android/tools/r8/shaking/allowshrinking/KeepAllowShrinkingIncludeDescriptorClassesCompatibilityTest.java
@@ -0,0 +1,120 @@
+// 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.shaking.allowshrinking;
+
+import static com.android.tools.r8.utils.codeinspector.Matchers.isPresent;
+import static com.android.tools.r8.utils.codeinspector.Matchers.isPresentAndNotRenamed;
+import static org.hamcrest.CoreMatchers.not;
+import static org.hamcrest.MatcherAssert.assertThat;
+
+import com.android.tools.r8.TestBase;
+import com.android.tools.r8.TestParameters;
+import com.android.tools.r8.TestShrinkerBuilder;
+import com.android.tools.r8.utils.codeinspector.ClassSubject;
+import com.google.common.collect.ImmutableList;
+import java.util.List;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.Parameterized;
+import org.junit.runners.Parameterized.Parameters;
+
+@RunWith(Parameterized.class)
+public class KeepAllowShrinkingIncludeDescriptorClassesCompatibilityTest extends TestBase {
+
+  private final TestParameters parameters;
+  private final Shrinker shrinker;
+
+  @Parameters(name = "{0}, {1}")
+  public static List<Object[]> data() {
+    return buildParameters(
+        getTestParameters().withCfRuntimes().build(), ImmutableList.of(Shrinker.R8, Shrinker.PG));
+  }
+
+  public KeepAllowShrinkingIncludeDescriptorClassesCompatibilityTest(
+      TestParameters parameters, Shrinker shrinker) {
+    this.parameters = parameters;
+    this.shrinker = shrinker;
+  }
+
+  @Test
+  public void test() throws Exception {
+    if (shrinker.isPG()) {
+      run(testForProguard(shrinker.getProguardVersion()).addDontWarn(getClass()));
+    } else {
+      run(testForR8(parameters.getBackend()));
+    }
+  }
+
+  private <T extends TestShrinkerBuilder<?, ?, ?, ?, T>> void run(T builder) throws Exception {
+    builder
+        .addProgramClasses(TestClass.class, A.class, B.class, SoftPinned.class)
+        .addKeepClassAndMembersRules(TestClass.class)
+        .addKeepRules(
+            "-keepclassmembers,allowshrinking,includedescriptorclasses class "
+                + SoftPinned.class.getTypeName()
+                + " { <methods>; }")
+        .run(parameters.getRuntime(), TestClass.class)
+        .assertSuccessWithOutputLines("true")
+        .inspect(
+            inspector -> {
+              assertThat(inspector.clazz(TestClass.class), isPresent());
+
+              ClassSubject softPinnedClass = inspector.clazz(SoftPinned.class);
+              assertThat(softPinnedClass.uniqueMethodWithName("used"), isPresentAndNotRenamed());
+              assertThat(softPinnedClass.uniqueMethodWithName("unused"), not(isPresent()));
+
+              // SoftPinned.used(A) remains thus A must be present and not renamed.
+              assertThat(inspector.clazz(A.class), isPresentAndNotRenamed());
+
+              // TODO(b/171548534): Unexpectedly the behavior here is that the class B is also not
+              //  renamed. It appears that both R8 and PG will eagerly mark the name as not needing
+              //  to be  renamed.
+              assertThat(inspector.clazz(B.class), isPresentAndNotRenamed());
+            });
+  }
+
+  static class A {
+    @Override
+    public String toString() {
+      return getClass().getTypeName();
+    }
+  }
+
+  static class B {
+    @Override
+    public String toString() {
+      return getClass().getTypeName();
+    }
+  }
+
+  static class SoftPinned {
+
+    public static void used(A a) {
+      System.out.println(a.toString().endsWith(System.nanoTime() > 0 ? "A" : "junk"));
+    }
+
+    public static void unused(B b) {
+      System.out.println(b.toString().endsWith(System.nanoTime() > 0 ? "B" : "junk"));
+    }
+  }
+
+  static class TestClass {
+
+    // Kept helper so the classes A and B escape and prohibit removal.
+    public static void kept(Object o) {
+      if (System.nanoTime() < 0) {
+        System.out.println(o.toString());
+      }
+    }
+
+    public static void main(String[] args) {
+      A a = new A();
+      B b = new B();
+      kept(a);
+      kept(b);
+      SoftPinned.used(a);
+    }
+  }
+}