diff --git a/extensions/css-language-features/client/src/customData.ts b/extensions/css-language-features/client/src/customData.ts
index c9954de8c51..8ba0770235a 100644
--- a/extensions/css-language-features/client/src/customData.ts
+++ b/extensions/css-language-features/client/src/customData.ts
@@ -43,7 +43,7 @@ export function getCustomDataPathsFromAllExtensions(): string[] {
 	for (const extension of extensions.all) {
 		const contributes = extension.packageJSON && extension.packageJSON.contributes;
 
-		if (contributes && contributes.css && contributes.css.customData && Array.isArray(contributes.css.customData)) {
+		if (contributes && contributes.css && contributes.css.experimental.customData && Array.isArray(contributes.css.experimental.customData)) {
 			const relativePaths: string[] = contributes.css.customData;
 			relativePaths.forEach(rp => {
 				dataPaths.push(path.resolve(extension.extensionPath, rp));
diff --git a/extensions/html-language-features/client/src/customData.ts b/extensions/html-language-features/client/src/customData.ts
index 467940bc736..8e9bf2863b6 100644
--- a/extensions/html-language-features/client/src/customData.ts
+++ b/extensions/html-language-features/client/src/customData.ts
@@ -45,7 +45,7 @@ export function getCustomDataPathsFromAllExtensions(): string[] {
 	for (const extension of extensions.all) {
 		const contributes = extension.packageJSON && extension.packageJSON.contributes;
 
-		if (contributes && contributes.html && contributes.html.customData && Array.isArray(contributes.html.customData)) {
+		if (contributes && contributes.html && contributes.html.experimental.customData && Array.isArray(contributes.html.experimental.customData)) {
 			const relativePaths: string[] = contributes.html.customData;
 			relativePaths.forEach(rp => {
 				dataPaths.push(path.resolve(extension.extensionPath, rp));