diff --git a/test/sharness/t0118-gateway-car.sh b/test/sharness/t0118-gateway-car.sh
index 62b2725d0cd5..c49f528c2a8d 100755
--- a/test/sharness/t0118-gateway-car.sh
+++ b/test/sharness/t0118-gateway-car.sh
@@ -92,7 +92,7 @@ test_launch_ipfs_daemon_without_network
 
     # CAR is streamed, gateway may not have the entire thing, unable to calculate total size
     test_expect_success "GET response for application/vnd.ipld.car includes no Content-Length" '
-    grep -qv "< Content-Length:" curl_output
+    test_should_not_contain "< Content-Length:" curl_output
     '
 
     test_expect_success "GET response for application/vnd.ipld.car includes Content-Disposition" '