diff --git a/dev/core/src/com/google/gwt/dev/jjs/impl/Devirtualizer.java b/dev/core/src/com/google/gwt/dev/jjs/impl/Devirtualizer.java
index bdcb8b3..795a91c 100644
--- a/dev/core/src/com/google/gwt/dev/jjs/impl/Devirtualizer.java
+++ b/dev/core/src/com/google/gwt/dev/jjs/impl/Devirtualizer.java
@@ -175,7 +175,7 @@
         JMethod jsoStaticImpl =
             staticImplCreator.getOrCreateStaticImpl(program, overridingMethod);
         devirtualMethodByMethod.put(method, jsoStaticImpl);
-      } else if (method.isJsOverlay()) {
+      } else if (isOverlayMethod(method)) {
         // A virtual dispatch on a target that is already known to be a JavaScriptObject, this
         // should have been handled by MakeCallsStatic.
         // TODO(rluble): verify that this case can not arise in optimized mode and if so
@@ -200,7 +200,7 @@
       if (devirtualMethodByMethod.containsKey(method)) {
         return true;
       }
-      if (method.isJsOverlay()) {
+      if (isOverlayMethod(method)) {
         return true;
       }
       if (method.getEnclosingType().isJsNative()) {
@@ -213,6 +213,18 @@
     }
   }
 
+  /**
+   * Returns true if {@code method} is an overlay method. Overlay methods include the ones that
+   * are marked as JsOverlay but also (synthetic) private instance methods on interfaces.
+   * <p>
+   * Synthetic private methods on interfaces are the result of lambdas that capture the enclosing
+   * instance and are defined on default methods.
+   */
+  private boolean isOverlayMethod(JMethod method) {
+    return method.isJsOverlay()
+        || (method.getEnclosingType() instanceof JInterfaceType && method.isPrivate());
+  }
+
   public static void exec(JProgram program) {
     new Devirtualizer(program).execImpl();
   }
diff --git a/user/test-super/com/google/gwt/dev/jjs/super/com/google/gwt/dev/jjs/test/Java8Test.java b/user/test-super/com/google/gwt/dev/jjs/super/com/google/gwt/dev/jjs/test/Java8Test.java
index 5c9d601..d38bf76 100644
--- a/user/test-super/com/google/gwt/dev/jjs/super/com/google/gwt/dev/jjs/test/Java8Test.java
+++ b/user/test-super/com/google/gwt/dev/jjs/super/com/google/gwt/dev/jjs/test/Java8Test.java
@@ -1576,4 +1576,28 @@
   public void testNativeJsOverlay_lambda() {
     assertSame("Hello", NativeClassWithJsOverlay.m("Hello"));
   }
+
+  interface IntefaceWithDefaultMethodAndLambda {
+    boolean f();
+
+    default BooleanPredicate fAsPredicate() {
+      // This lambda will be defined as an instance method in the enclosing class, which is an
+      // interface. In this case the methdod will be devirtualized.
+      return () -> this.f();
+    }
+  }
+
+  interface BooleanPredicate {
+    boolean apply();
+  }
+
+  public void testLambdaCapturingThis_onDefaultMethod() {
+    assertTrue(
+        new IntefaceWithDefaultMethodAndLambda() {
+          @Override
+          public boolean f() {
+            return true;
+          }
+        }.fAsPredicate().apply());
+  }
 }
diff --git a/user/test/com/google/gwt/dev/jjs/test/Java8Test.java b/user/test/com/google/gwt/dev/jjs/test/Java8Test.java
index 1fda5c6..e435da0 100644
--- a/user/test/com/google/gwt/dev/jjs/test/Java8Test.java
+++ b/user/test/com/google/gwt/dev/jjs/test/Java8Test.java
@@ -292,6 +292,10 @@
     assertFalse(isGwtSourceLevel8());
   }
 
+  public void testLambdaCapturingThis_onDefaultMethod() {
+    assertFalse(isGwtSourceLevel8());
+  }
+
   private boolean isGwtSourceLevel8() {
     return JUnitShell.getCompilerOptions().getSourceLevel().compareTo(SourceLevel.JAVA8) >= 0;
   }