diff --git a/tools/auto_update_v8.ts b/tools/auto_update_v8.ts
index 98355a96..eaba0c11 100644
--- a/tools/auto_update_v8.ts
+++ b/tools/auto_update_v8.ts
@@ -52,7 +52,7 @@ console.log(`Updated to version ${newVersion}`);
 // Update version in readme
 let readme = Deno.readTextFileSync("README.md");
 readme = readme.replace(
-  /V8 Version: .*$/,
+  /V8 Version: \S+/,
   `V8 Version: ${newVersion}`,
 );
 Deno.writeTextFileSync("README.md", readme);