diff --git a/contrib/func.sh b/contrib/func.sh
index 47be7ad4..6d840138 100644
--- a/contrib/func.sh
+++ b/contrib/func.sh
@@ -1,13 +1,14 @@
 #!/usr/bin/env sh
-# The github-pages function optionally takes two arguments
-#  - the first argument is the path to the Jekyll site
-#  - the second argument is the port number
+# The github-pages function optionally reads two environment variables
+#  - the first is the path to the Jekyll site (GH_PATH)
+#  - the second is the port number (GH_PORT)
+
 function github-pages {
-  _path=${1:-.}
-  _port=${2:-4000}
+  _path=${GH_PATH:-.}
+  _port=${GH_PORT:-4000}
   docker run --rm \
     -p $_port:4000 \
     -u `id -u`:`id -g` \
     -v `realpath $_path`:/src/site \
-    gh-pages
+    gh-pages jekyll serve -H 0.0.0.0 -P 4000 $@
 }