diff --git a/packages/macp/src/gate-runner.ts b/packages/macp/src/gate-runner.ts
index 40c971a..b59f807 100644
--- a/packages/macp/src/gate-runner.ts
+++ b/packages/macp/src/gate-runner.ts
@@ -43,7 +43,7 @@ export function runShell(
   let timedOut = false;
 
   try {
-    const result = spawnSync('bash', ['-lc', command], {
+    const result = spawnSync('sh', ['-c', command], {
       cwd,
       timeout: Math.max(1, timeoutSec) * 1000,
       encoding: 'utf-8',