diff --git a/bin/firewall-sosdg b/bin/firewall-sosdg
index b08721b..f6d7529 100755
--- a/bin/firewall-sosdg
+++ b/bin/firewall-sosdg
@@ -164,8 +164,8 @@ if [ "$BLOCK_INCOMING_RFC1918" ]; then
 		for i in $BLOCK_INCOMING_RFC1918; do
 			display_c BLUE "$i" N
 			for x in $RFC1918_SPACE; do
-				$IPTABLES -A OUTPUT -s $i -s $x -j DROP
-				$IPTABLES -A FORWARD -s $i -s $x -j DROP
+				$IPTABLES -A OUTPUT -i $i -s $x -j DROP
+				$IPTABLES -A FORWARD -i $i -s $x -j DROP
 			done
 		done
 		echo -ne "\n"