diff --git a/Shorewall-init/install.sh b/Shorewall-init/install.sh
index 80cf72d0d..da34880a3 100755
--- a/Shorewall-init/install.sh
+++ b/Shorewall-init/install.sh
@@ -109,7 +109,9 @@ finished=0
 configure=1
 
 while [ $finished -eq 0 ] ; do
-    case "$1" in
+    option="$1"
+
+    case "$option" in
 	-*)
 	    option=${option#-}