diff --git a/src/utils.ts b/src/utils.ts
index 6751d40..6c66416 100644
--- a/src/utils.ts
+++ b/src/utils.ts
@@ -142,7 +142,7 @@ export function prettyTime(diff: number) {
 }
 
 export async function exec(cmd: string, args: string[], cwd: string) {
-  const cp = spawn(cmd, args, { stdio: "inherit", cwd });
+  const cp = spawn(cmd, args, { stdio: "inherit", cwd, shell: true });
 
   return new Promise<void>((resolve) => {
     cp.on("exit", (code) => {
diff --git a/test/test_utils.ts b/test/test_utils.ts
index d8b883a..8193622 100644
--- a/test/test_utils.ts
+++ b/test/test_utils.ts
@@ -15,7 +15,8 @@ export interface PkgJson {
 
 export async function runJsr(args: string[], cwd: string) {
   const bin = path.join(__dirname, "..", "src", "bin.ts");
-  return await exec("npx", ["ts-node", bin, ...args], cwd);
+  const tsNode = path.join(__dirname, "..", "node_modules", ".bin", "ts-node");
+  return await exec(tsNode, [bin, ...args], cwd);
 }
 
 export async function withTempEnv(