diff --git a/Shorewall-core/lib.cli b/Shorewall-core/lib.cli
index b86940312..9f991c62b 100644
--- a/Shorewall-core/lib.cli
+++ b/Shorewall-core/lib.cli
@@ -1959,7 +1959,7 @@ add_command() {
 		ipset=6_${zone}_${interface};
 	    fi
 
-	    ipset=$(echo $ipset | sed 's/./_/g');
+	    ipset=$(echo $ipset | sed 's/\./_/g');
 
 	    if ! qt $IPSET -L $ipset; then
 		fatal_error "Zone $zone, interface $interface does not have a dynamic host list"