diff --git a/src/main/java/com/google/devtools/build/lib/packages/StarlarkSemanticsOptions.java b/src/main/java/com/google/devtools/build/lib/packages/StarlarkSemanticsOptions.java
index 07a6e50..d5fa77f 100644
--- a/src/main/java/com/google/devtools/build/lib/packages/StarlarkSemanticsOptions.java
+++ b/src/main/java/com/google/devtools/build/lib/packages/StarlarkSemanticsOptions.java
@@ -239,7 +239,7 @@
   // 3) Remove --check_third_party_targets_have_licenses.
   @Option(
       name = "incompatible_disable_third_party_license_checking",
-      defaultValue = "false",
+      defaultValue = "true",
       documentationCategory = OptionDocumentationCategory.STARLARK_SEMANTICS,
       effectTags = OptionEffectTag.BUILD_FILE_SEMANTICS,
       metadataTags = {
diff --git a/src/main/java/com/google/devtools/build/lib/syntax/StarlarkSemantics.java b/src/main/java/com/google/devtools/build/lib/syntax/StarlarkSemantics.java
index 4a84325..cf60461 100644
--- a/src/main/java/com/google/devtools/build/lib/syntax/StarlarkSemantics.java
+++ b/src/main/java/com/google/devtools/build/lib/syntax/StarlarkSemantics.java
@@ -209,7 +209,7 @@
           .incompatibleBzlDisallowLoadAfterStatement(true)
           .incompatibleDepsetIsNotIterable(false)
           .incompatibleDepsetUnion(false)
-          .incompatibleDisableThirdPartyLicenseChecking(false)
+          .incompatibleDisableThirdPartyLicenseChecking(true)
           .incompatibleDisableDeprecatedAttrParams(false)
           .incompatibleDisableObjcProviderResources(false)
           .incompatibleDisallowDictPlus(true)