diff --git a/scripts/update-docs.sh b/scripts/update-docs.sh
index b64baf394..b953936cf 100755
--- a/scripts/update-docs.sh
+++ b/scripts/update-docs.sh
@@ -3,5 +3,11 @@
 # exit when any command fails
 set -e
 
+if [ -z "$1" ]; then
+  ARG=-r
+else
+  ARG=$1
+fi
+
 cog $ARG website/index.md
 cog $ARG website/docs/usage.md