diff --git a/src/runner.sh b/src/runner.sh
index 4b39d6b..d52b8d7 100755
--- a/src/runner.sh
+++ b/src/runner.sh
@@ -545,7 +545,7 @@ main() (
 
 		# Kill runner process.
 		log_info "Kill runner process with pid '${pid}'."
-		if ! ps -p "${pid}"; then
+		if ! ps -p "${pid}" >/dev/null; then
 			fail "Runner process with pid='${pid}' is not running." \
 				"${err_runner_process_not_running}"
 		fi