diff --git a/Shorewall/Perl/Shorewall/ARP.pm b/Shorewall/Perl/Shorewall/ARP.pm
index 37198ceb0..b8f4411da 100644
--- a/Shorewall/Perl/Shorewall/ARP.pm
+++ b/Shorewall/Perl/Shorewall/ARP.pm
@@ -120,7 +120,7 @@ sub process_arprule() {
 		    );
 
     if ( supplied $newaddr ) {
-	fatal_error "The $action ACTION does not allow a new address" unless $action =~ /^SNAT|DNAT|SMAT|DMAT$/;
+	fatal_error "The $action ACTION does not allow a new address" unless $action =~ /^(?:SNAT|DNAT|SMAT|DMAT)C?$/;
     } else {
 	fatal_error "The $action ACTION requires a new address" if $action =~ /^SNAT|DNAT|SMAT|DMAT$/;
     }