diff --git a/Shorewall/Perl/Shorewall/Config.pm b/Shorewall/Perl/Shorewall/Config.pm
index 3f9355a91..f1488d87d 100644
--- a/Shorewall/Perl/Shorewall/Config.pm
+++ b/Shorewall/Perl/Shorewall/Config.pm
@@ -3496,7 +3496,7 @@ sub GeoIP_Match() {
 }
 
 sub Checksum_Target() {
-    have_capability 'MANGLE_ENABLED' && qt1( "iptables -t mangle -A $sillyname -j CHECKSUM --checksum-fill" );
+    have_capability 'MANGLE_ENABLED' && qt1( "$iptables -t mangle -A $sillyname -j CHECKSUM --checksum-fill" );
 }
 
 our %detect_capability =