diff --git a/src/test/java/com/google/devtools/build/lib/packages/SkylarkSemanticsConsistencyTest.java b/src/test/java/com/google/devtools/build/lib/packages/SkylarkSemanticsConsistencyTest.java
index 933ef11..3ce2097 100644
--- a/src/test/java/com/google/devtools/build/lib/packages/SkylarkSemanticsConsistencyTest.java
+++ b/src/test/java/com/google/devtools/build/lib/packages/SkylarkSemanticsConsistencyTest.java
@@ -141,6 +141,7 @@
         "--incompatible_expand_directories=" + rand.nextBoolean(),
         "--incompatible_generate_javacommon_source_jar=" + rand.nextBoolean(),
         "--incompatible_new_actions_api=" + rand.nextBoolean(),
+        "--incompatible_no_output_attr_default=" + rand.nextBoolean(),
         "--incompatible_no_support_tools_in_action_inputs=" + rand.nextBoolean(),
         "--incompatible_no_target_output_group=" + rand.nextBoolean(),
         "--incompatible_no_transitive_loads=" + rand.nextBoolean(),
@@ -182,6 +183,7 @@
         .incompatibleExpandDirectories(rand.nextBoolean())
         .incompatibleGenerateJavaCommonSourceJar(rand.nextBoolean())
         .incompatibleNewActionsApi(rand.nextBoolean())
+        .incompatibleNoOutputAttrDefault(rand.nextBoolean())
         .incompatibleNoSupportToolsInActionInputs(rand.nextBoolean())
         .incompatibleNoTargetOutputGroup(rand.nextBoolean())
         .incompatibleNoTransitiveLoads(rand.nextBoolean())
diff --git a/src/test/java/com/google/devtools/build/lib/skylark/SkylarkIntegrationTest.java b/src/test/java/com/google/devtools/build/lib/skylark/SkylarkIntegrationTest.java
index c8734de..9d4a1e3 100644
--- a/src/test/java/com/google/devtools/build/lib/skylark/SkylarkIntegrationTest.java
+++ b/src/test/java/com/google/devtools/build/lib/skylark/SkylarkIntegrationTest.java
@@ -1053,6 +1053,90 @@
   }
 
   @Test
+  public void testNoOutputAttrDefault() throws Exception {
+    setSkylarkSemanticsOptions("--incompatible_no_output_attr_default=true");
+
+    scratch.file(
+        "test/extension.bzl",
+        "def custom_rule_impl(ctx):",
+        "  out_file = ctx.actions.declare_file(ctx.attr._o1.name)",
+        "  ctx.actions.write(output=out_file, content='hi')",
+        "  return struct(o1=ctx.attr._o1)",
+        "",
+        "def output_fn():",
+        "  return Label('//test/skylark:foo.txt')",
+        "",
+        "custom_rule = rule(implementation = custom_rule_impl,",
+        "  attrs = {'_o1': attr.output(default = output_fn)})");
+
+    scratch.file(
+        "test/BUILD",
+        "load('//test:extension.bzl', 'custom_rule')",
+        "",
+        "custom_rule(name = 'r')");
+
+    reporter.removeHandler(failFastHandler);
+    getConfiguredTarget("//test:r");
+    assertContainsEvent("'default' is no longer a supported parameter for attr.output");
+  }
+
+  @Test
+  public void testNoOutputListAttrDefault() throws Exception {
+    setSkylarkSemanticsOptions("--incompatible_no_output_attr_default=true");
+
+    scratch.file(
+        "test/extension.bzl",
+        "def custom_rule_impl(ctx):",
+        "  return []",
+        "",
+        "custom_rule = rule(implementation = custom_rule_impl,",
+        "  attrs = {'outs': attr.output_list(default = [])})");
+
+    scratch.file(
+        "test/BUILD",
+        "load('//test:extension.bzl', 'custom_rule')",
+        "",
+        "custom_rule(name = 'r')");
+
+    reporter.removeHandler(failFastHandler);
+    getConfiguredTarget("//test:r");
+    assertContainsEvent("'default' is no longer a supported parameter for attr.output_list");
+  }
+
+  @Test
+  public void testLegacyOutputAttrDefault() throws Exception {
+    // Note that use of the "default" parameter of attr.output and attr.output_label is deprecated
+    // and barely functional. This test simply serves as proof-of-concept verification that the
+    // legacy behavior remains intact.
+    setSkylarkSemanticsOptions("--incompatible_no_output_attr_default=false");
+
+    scratch.file(
+        "test/skylark/extension.bzl",
+        "def custom_rule_impl(ctx):",
+        "  out_file = ctx.actions.declare_file(ctx.attr._o1.name)",
+        "  ctx.actions.write(output=out_file, content='hi')",
+        "  return struct(o1=ctx.attr._o1,",
+        "                o2=ctx.attr.o2)",
+        "",
+        "def output_fn():",
+        "  return Label('//test/skylark:foo.txt')",
+        "",
+        "custom_rule = rule(implementation = custom_rule_impl,",
+        "  attrs = {'_o1': attr.output(default = output_fn),",
+        "           'o2': attr.output_list(default = [])})");
+
+    scratch.file(
+        "test/skylark/BUILD",
+        "load('//test/skylark:extension.bzl', 'custom_rule')",
+        "",
+        "custom_rule(name = 'cr')");
+
+    ConfiguredTarget target = getConfiguredTarget("//test/skylark:cr");
+    assertThat(target.get("o1")).isEqualTo(Label.parseAbsoluteUnchecked("//test/skylark:foo.txt"));
+    assertThat(target.get("o2")).isEqualTo(MutableList.empty());
+  }
+
+  @Test
   public void testRuleClassNonMandatoryEmptyOutputs() throws Exception {
     scratch.file(
         "test/skylark/extension.bzl",