diff --git a/src/test/java/com/android/tools/r8/classmerging/vertical/MergeSynthesizingContextIntoSyntheticLambdaTest.java b/src/test/java/com/android/tools/r8/classmerging/vertical/MergeSynthesizingContextIntoSyntheticLambdaTest.java
new file mode 100644
index 0000000..069d4f7
--- /dev/null
+++ b/src/test/java/com/android/tools/r8/classmerging/vertical/MergeSynthesizingContextIntoSyntheticLambdaTest.java
@@ -0,0 +1,78 @@
+// Copyright (c) 2021, 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.classmerging.vertical;
+
+import com.android.tools.r8.TestBase;
+import com.android.tools.r8.TestParameters;
+import com.android.tools.r8.TestParametersCollection;
+import com.android.tools.r8.utils.codeinspector.AssertUtils;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.Parameterized;
+
+@RunWith(Parameterized.class)
+public class MergeSynthesizingContextIntoSyntheticLambdaTest extends TestBase {
+
+  private final TestParameters parameters;
+
+  @Parameterized.Parameters(name = "{0}")
+  public static TestParametersCollection data() {
+    return getTestParameters().withAllRuntimesAndApiLevels().build();
+  }
+
+  public MergeSynthesizingContextIntoSyntheticLambdaTest(TestParameters parameters) {
+    this.parameters = parameters;
+  }
+
+  @Test
+  public void test() throws Exception {
+    AssertUtils.assertFailsCompilationIf(
+        parameters.isDexRuntime(),
+        () -> {
+          testForR8(parameters.getBackend())
+              .addInnerClasses(getClass())
+              .addKeepMainRule(Main.class)
+              // Disable inlining to ensure that the synthetic lambdas remain in the residual
+              // program.
+              .addOptionsModification(options -> options.enableInlining = false)
+              .addVerticallyMergedClassesInspector(
+                  inspector -> {
+                    if (parameters.isCfRuntime()) {
+                      inspector.assertNoClassesMerged();
+                    } else {
+                      inspector.assertMergedIntoSubtype(I.class);
+                    }
+                  })
+              .setMinApi(parameters.getApiLevel())
+              .compile()
+              .run(parameters.getRuntime(), Main.class)
+              .assertSuccessWithOutputLines("I", "J");
+        });
+  }
+
+  static class Main {
+    public static void main(String[] args) {
+      I i = () -> System.out.println("I");
+      i.f();
+      i.g().h();
+    }
+  }
+
+  interface I {
+
+    void f();
+
+    default J g() {
+      // Has synthesizing context I. After vertical class merging, this synthesizing context is
+      // rewritten into the synthetic lambda defined in main().
+      return () -> System.out.println("J");
+    }
+  }
+
+  interface J {
+
+    void h();
+  }
+}