diff --git a/src/vs/workbench/api/common/extHostWebview.ts b/src/vs/workbench/api/common/extHostWebview.ts
index 2eb67a7bf10e6..4d5a5fdd791df 100644
--- a/src/vs/workbench/api/common/extHostWebview.ts
+++ b/src/vs/workbench/api/common/extHostWebview.ts
@@ -85,7 +85,11 @@ export class ExtHostWebview implements vscode.Webview {
 			}
 			return extensionCspRule + ' ' + webviewGenericCspSource;
 		}
-		return webviewGenericCspSource;
+		/**
+		 * When not using a CDN content loads from self.
+		 * @author coder
+		 */
+		return `'self' ` + webviewGenericCspSource;
 	}
 
 	public get html(): string {