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 5b08481..294d329 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
@@ -143,6 +143,7 @@
         "--incompatible_disallow_legacy_java_provider=" + rand.nextBoolean(),
         "--incompatible_disallow_load_labels_to_cross_package_boundaries=" + rand.nextBoolean(),
         "--incompatible_disallow_native_in_build_file=" + rand.nextBoolean(),
+        "--incompatible_disallow_old_octal_notation=" + rand.nextBoolean(),
         "--incompatible_disallow_old_style_args_add=" + rand.nextBoolean(),
         "--incompatible_disallow_struct_provider_syntax=" + rand.nextBoolean(),
         "--incompatible_expand_directories=" + rand.nextBoolean(),
@@ -190,6 +191,7 @@
         .incompatibleDisallowLegacyJavaProvider(rand.nextBoolean())
         .incompatibleDisallowLoadLabelsToCrossPackageBoundaries(rand.nextBoolean())
         .incompatibleDisallowNativeInBuildFile(rand.nextBoolean())
+        .incompatibleDisallowOldOctalNotation(rand.nextBoolean())
         .incompatibleDisallowOldStyleArgsAdd(rand.nextBoolean())
         .incompatibleDisallowStructProviderSyntax(rand.nextBoolean())
         .incompatibleExpandDirectories(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 ab46118..43b5c4b 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
@@ -2964,4 +2964,28 @@
       }
     }
   }
+
+  @Test
+  public void testOldOctalNotationIsForbidden() throws Exception {
+    setSkylarkSemanticsOptions("--incompatible_disallow_old_octal_notation=true");
+
+    scratch.file("test/extension.bzl", "y = 0246");
+
+    scratch.file("test/BUILD", "load('//test:extension.bzl', 'y')", "cc_library(name = 'r')");
+
+    reporter.removeHandler(failFastHandler);
+    getConfiguredTarget("//test:r");
+    assertContainsEvent("Invalid octal value `0246`, should be: `0o246`");
+  }
+
+  @Test
+  public void testOldOctalNotation() throws Exception {
+    setSkylarkSemanticsOptions("--incompatible_disallow_old_octal_notation=false");
+
+    scratch.file("test/extension.bzl", "y = 0246");
+
+    scratch.file("test/BUILD", "load('//test:extension.bzl', 'y')", "cc_library(name = 'r')");
+
+    getConfiguredTarget("//test:r");
+  }
 }