diff --git a/.gitea/workflows/isolation-check.yaml b/.gitea/workflows/isolation-check.yaml
index a8167ea..fc83701 100644
--- a/.gitea/workflows/isolation-check.yaml
+++ b/.gitea/workflows/isolation-check.yaml
@@ -83,7 +83,7 @@ jobs:
           172.18.0.1 172.19.0.1 172.20.0.1 172.21.0.1 172.22.0.1 172.23.0.1 \
           172.24.0.1 192.168.1.185; do
             echo -n "$subnet ... "
-            ping -4 -n -c 1 -W 250 $subnet >/dev/null 2>&1 && echo -n "ping response . "
+            ping -4 -n -c 1 -W 0.250 $subnet >/dev/null 2>&1 && echo -n "ping response . "
             curl -m 1 http://$subnet/ >/dev/null 2>&1 && echo -n "HTTP response . "
             curl -m 1 http://$subnet:8098/docker-compose.yaml >/dev/null 2>&1 && echo -n "HTTP 8098 response . "
             echo ''