diff --git a/jsonc/testdata/JSONTestSuite/test.ts b/jsonc/testdata/JSONTestSuite/test.ts
index a430654f3955..5055581bbbde 100644
--- a/jsonc/testdata/JSONTestSuite/test.ts
+++ b/jsonc/testdata/JSONTestSuite/test.ts
@@ -18,7 +18,9 @@ function getError<T>(
 
 // Make sure that the JSON.parse and JSONC.parse results match.
 for await (
-  const dirEntry of walk(fromFileUrl(new URL("./", import.meta.url)))
+  const dirEntry of walk(fromFileUrl(new URL("./", import.meta.url)), {
+    exts: [".json"],
+  })
 ) {
   if (!dirEntry.isFile) {
     continue;
@@ -30,12 +32,12 @@ for await (
     async fn() {
       const text = await Deno.readTextFile(dirEntry.path);
 
-      const [hasJsonError, jsonError, jsonResult] = getError(() => {
-        JSON.parse(text);
-      });
-      const [hasJsoncError, jsoncError, jsoncResult] = getError(() => {
-        JSONC.parse(text);
-      });
+      const [hasJsonError, jsonError, jsonResult] = getError(() =>
+        JSON.parse(text)
+      );
+      const [hasJsoncError, jsoncError, jsoncResult] = getError(() =>
+        JSONC.parse(text)
+      );
 
       // If an error occurs in JSON.parse() but no error occurs in JSONC.parse(), or vice versa, an error is thrown.
       if (hasJsonError !== hasJsoncError) {