diff --git a/extensions/typescript-language-features/src/typescriptServiceClient.ts b/extensions/typescript-language-features/src/typescriptServiceClient.ts
index c77c86f7c9abc8fdc40b2167e03c95e10ab876a0..f45cb960dca54b94309314b56c4c3457b3857d52 100644
--- a/extensions/typescript-language-features/src/typescriptServiceClient.ts
+++ b/extensions/typescript-language-features/src/typescriptServiceClient.ts
@@ -575,11 +575,15 @@ export default class TypeScriptServiceClient extends Disposable implements IType
 			return undefined;
 		}
 
-		const result = resource.fsPath;
+		let result = resource.fsPath;
 		if (!result) {
 			return undefined;
 		}
 
+		if (resource.scheme === fileSchemes.file) {
+			result = path.normalize(result);
+		}
+
 		// Both \ and / must be escaped in regular expressions
 		return result.replace(new RegExp('\\' + this.pathSeparator, 'g'), '/');
 	}