diff --git a/packages/cli/src/utils/sandbox.ts b/packages/cli/src/utils/sandbox.ts
index 3a8914ee..cc51a327 100644
--- a/packages/cli/src/utils/sandbox.ts
+++ b/packages/cli/src/utils/sandbox.ts
@@ -306,7 +306,7 @@ export async function start_sandbox(sandbox: string) {
       );
       if (isCustomProjectSandbox) {
         console.error(`using ${projectSandboxDockerfile} for sandbox`);
-        buildArgs += `-s -f ${path.resolve(projectSandboxDockerfile)} -i ${image}`;
+        buildArgs += `-f ${path.resolve(projectSandboxDockerfile)} -i ${image}`;
       }
       execSync(`cd ${gcRoot} && scripts/build_sandbox.sh -s ${buildArgs}`, {
         stdio: 'inherit',