diff --git a/Shorewall/Perl/Shorewall/Tc.pm b/Shorewall/Perl/Shorewall/Tc.pm
index 9d00cfa..338388b 100644
--- a/Shorewall/Perl/Shorewall/Tc.pm
+++ b/Shorewall/Perl/Shorewall/Tc.pm
@@ -394,11 +394,11 @@ sub process_tc_rule( ) {
 					      }
 					  }
 
-					  $cmd =~ /^TTL\(([-+]?\d+)\)$/;
+					  $cmd =~ /^TTL\(([-+]?(\d+))\)$/;
 
 					  my $param =  $1;
 
-					  fatal_error "Invalid TTL specification( $cmd )" unless $param && ( $param = abs $param ) < 256;
+					  fatal_error "Invalid TTL specification( $cmd )" unless $2 && ( $param = abs $param ) < 256;
 
 					  if ( $1 =~ /^\+/ ) {
 					      $target .= " --ttl-inc $param";
@@ -422,11 +422,11 @@ sub process_tc_rule( ) {
 					      }
 					  }
 
-					  $cmd =~ /^HL\(([-+]?\d+)\)$/;
+					  $cmd =~ /^HL\(([-+]?(\d+))\)$/;
 
 					  my $param =  $1;
 
-					  fatal_error "Invalid HL specification( $cmd )" unless $param && ( $param = abs $param ) < 256;
+					  fatal_error "Invalid HL specification( $cmd )" unless $2 && ( $param = abs $param ) < 256;
 
 					  if ( $1 =~ /^\+/ ) {
 					      $target .= " --hl-inc $param";