diff --git a/extensions/vscode-api-tests/package.json b/extensions/vscode-api-tests/package.json
index d56cbf59bb1..bcc31d3667a 100644
--- a/extensions/vscode-api-tests/package.json
+++ b/extensions/vscode-api-tests/package.json
@@ -18,6 +18,7 @@
     "defaultChatParticipant",
     "diffCommand",
     "documentFiltersExclusive",
+    "documentSyntaxHighlighting",
     "editorInsets",
     "embeddings",
     "envIsConnectionMetered",
diff --git a/src/vs/workbench/services/extensions/common/extensions.ts b/src/vs/workbench/services/extensions/common/extensions.ts
index b4a8251394c..c7fee71a2e2 100644
--- a/src/vs/workbench/services/extensions/common/extensions.ts
+++ b/src/vs/workbench/services/extensions/common/extensions.ts
@@ -324,7 +324,7 @@ export function isProposedApiEnabled(extension: IExtensionDescription, proposal:
 	if (!extension.enabledApiProposals) {
 		return false;
 	}
-	return true;// extension.enabledApiProposals.includes(proposal);
+	return extension.enabledApiProposals.includes(proposal);
 }
 
 export function checkProposedApiEnabled(extension: IExtensionDescription, proposal: ApiProposalName): void {