diff --git a/Shorewall/action.Broadcast b/Shorewall/action.Broadcast
index 7c85a0723..38fe75d0d 100644
--- a/Shorewall/action.Broadcast
+++ b/Shorewall/action.Broadcast
@@ -40,7 +40,7 @@ use Shorewall::Chains;
 my ( $action, $audit ) = get_action_params( 2 );
 
 fatal_error "Invalid parameter ($audit) to action Broadcast"   if supplied $audit && $audit ne 'audit';
-fatal_error "Invalid parameter ($action) to action Broadcast"  unless $action =~ /^ACCEPT|DROP|REJECT$/;
+fatal_error "Invalid parameter ($action) to action Broadcast"  unless $action =~ /^(?:ACCEPT|DROP|REJECT)$/;
 
 my $chainref           = get_action_chain;
 my ( $level, $tag )    = get_action_logging;
diff --git a/Shorewall/action.Invalid b/Shorewall/action.Invalid
index a8aabbbe8..7cae452a3 100644
--- a/Shorewall/action.Invalid
+++ b/Shorewall/action.Invalid
@@ -40,7 +40,7 @@ use Shorewall::Chains;
 my ( $action, $audit ) = get_action_params( 2 );
 
 fatal_error "Invalid parameter ($audit) to action Invalid"   if supplied $audit && $audit ne 'audit';
-fatal_error "Invalid parameter ($action) to action Invalid"  unless $action =~ /^ACCEPT|DROP|REJECT$/;
+fatal_error "Invalid parameter ($action) to action Invalid"  unless $action =~ /^(?:ACCEPT|DROP|REJECT)$/;
 
 my $chainref         = get_action_chain;
 my ( $level, $tag )  = get_action_logging;
diff --git a/Shorewall/action.NotSyn b/Shorewall/action.NotSyn
index ae2226f16..afd778d25 100644
--- a/Shorewall/action.NotSyn
+++ b/Shorewall/action.NotSyn
@@ -40,7 +40,7 @@ use Shorewall::Chains;
 my ( $action, $audit ) = get_action_params( 2 );
 
 fatal_error "Invalid parameter ($audit) to action NotSyn"   if supplied $audit && $audit ne 'audit';
-fatal_error "Invalid parameter ($action) to action NotSyn"  unless $action =~ /^ACCEPT|DROP|REJECT$/;
+fatal_error "Invalid parameter ($action) to action NotSyn"  unless $action =~ /^(?:ACCEPT|DROP|REJECT)$/;
 
 my $chainref         = get_action_chain;
 my ( $level, $tag )  = get_action_logging;