diff --git a/http-ts/BUILD b/http-ts/BUILD
index bfee475833..fa1224b88f 100644
--- a/http-ts/BUILD
+++ b/http-ts/BUILD
@@ -106,6 +106,7 @@ checkstyle_test(
         "tool/**/*",
     ]),
     exclude = glob([
+        ".npmrc",
         "**/*.json",
         "**/*.md",
         "pnpm-lock.yaml",
diff --git a/http-ts/src/response.ts b/http-ts/src/response.ts
index 6b2239001d..5b3b6b2145 100644
--- a/http-ts/src/response.ts
+++ b/http-ts/src/response.ts
@@ -100,9 +100,9 @@ export function isApiError(err: any): err is ApiError {
 export type ApiResponse<OK_RES = {} | null> = ApiOkResponse<OK_RES> | ApiErrorResponse;
 
 export function isOkResponse<OK_RES>(res: ApiResponse<OK_RES>): res is ApiOkResponse<OK_RES> {
-    return "ok" in res;
+    return typeof res === "object" && "ok" in res;
 }
 
 export function isApiErrorResponse(res: ApiResponse): res is ApiErrorResponse {
-    return "err" in res;
+    return typeof res === "object" && "err" in res;
 }