diff --git a/url/dirname_test.ts b/url/dirname_test.ts
index b9052cfd5aaa..4c9a25e93658 100755
--- a/url/dirname_test.ts
+++ b/url/dirname_test.ts
@@ -24,7 +24,7 @@ const TESTSUITE = [
     new URL("https://deno.land///"),
     new URL("https://deno.land"),
   ],
-];
+] as const;
 
 Deno.test("dirname()", function () {
   for (const [test_url, expected] of TESTSUITE) {
diff --git a/url/extname_test.ts b/url/extname_test.ts
index dafd40b0d354..ec2e63cb37fa 100755
--- a/url/extname_test.ts
+++ b/url/extname_test.ts
@@ -10,7 +10,7 @@ const TESTSUITE = [
   [new URL("https://deno.land/std/assert/mod.ts#header"), ".ts"],
   [new URL("https://deno.land/std/assert/mod."), "."],
   [new URL("https://deno.land/std/assert/mod"), ""],
-];
+] as const;
 
 Deno.test("extname()", function () {
   for (const [test_url, expected] of TESTSUITE) {
diff --git a/url/normalize_test.ts b/url/normalize_test.ts
index 2492f425df62..93d6a5f9656c 100755
--- a/url/normalize_test.ts
+++ b/url/normalize_test.ts
@@ -28,7 +28,7 @@ const TESTSUITE = [
     "https:/deno.land//..",
     new URL("https://deno.land"),
   ],
-];
+] as const;
 
 Deno.test("normalize()", function () {
   for (const [test_url, expected] of TESTSUITE) {