diff --git a/add.cgi b/add.cgi
index 44c2757..8e07d73 100755
--- a/add.cgi
+++ b/add.cgi
@@ -56,13 +56,15 @@ foreach my $clash ("AuthUserFile", "AuthType", "AuthName") {
 
 # Add protected directory in other webserver plugins
 foreach my $p (&virtual_server::list_feature_plugins()) {
-	my $err = &virtual_server::plugin_call($p,
-		"feature_add_protected_dir", $d, 
-			{ 'protected_dir' => $dir,
-			  'protected_user_file_path' => $usersfile, 
-			  'protected_user_file' => $htusers,
-			  'protected_name' => $in{'desc'} });
-	&error($err) if ($err);
+	if (&virtual_server::plugin_defined($p, "feature_add_protected_dir")) {
+		my $err = &virtual_server::plugin_call($p,
+			"feature_add_protected_dir", $d, 
+				{ 'protected_dir' => $dir,
+				  'protected_user_file_path' => $usersfile, 
+				  'protected_user_file' => $htusers,
+				  'protected_name' => $in{'desc'} });
+		&error($err) if ($err);
+		}
 	}
 
 # Create .htaccess (as domain owner)
diff --git a/delete.cgi b/delete.cgi
index 0f926ec..1569f94 100755
--- a/delete.cgi
+++ b/delete.cgi
@@ -25,11 +25,13 @@ foreach my $path (@d) {
 	if ($dir) {
 		# Delete protected directory in other webserver plugins
 		foreach my $p (&virtual_server::list_feature_plugins()) {
-			my $err = &virtual_server::plugin_call($p,
-				"feature_delete_protected_dir", $d,
-					{ 'protected_dir' => $dir->[0],
-					  'protected_user_file_path' => $dir->[1] });
-			&error($err) if ($err);
+			if (&virtual_server::plugin_defined($p, "feature_delete_protected_dir")) {
+				my $err = &virtual_server::plugin_call($p,
+					"feature_delete_protected_dir", $d,
+						{ 'protected_dir' => $dir->[0],
+						  'protected_user_file_path' => $dir->[1] });
+				&error($err) if ($err);
+				}
 			}
 		# Remove protection directives
 		no warnings "once";