diff --git a/tests/utils/proxy/start.sh b/tests/utils/proxy/start.sh
index c837cbb39..b237fc399 100755
--- a/tests/utils/proxy/start.sh
+++ b/tests/utils/proxy/start.sh
@@ -14,6 +14,6 @@ set -x
 
 start-stop-daemon --verbose --start --background --pidfile "$PIDFILE" --make-pidfile --exec "$PROXYBIN" -- "$ARGS"
 
-ps -p $(cat "$PIDFILE") u
+ps -p "$(cat "$PIDFILE")" u
 sleep 2
-ps -p $(cat "$PIDFILE") u
+ps -p "$(cat "$PIDFILE")" u