diff --git a/fulcrm_webhook.module b/fulcrm_webhook.module
index 291592d..d2ce2d2 100644
--- a/fulcrm_webhook.module
+++ b/fulcrm_webhook.module
@@ -49,22 +49,30 @@ function fulcrm_webhook_webhook( $uuid ) {
             $payload_error_msg = json_last_error_msg();
         }
 
-        switch ( $method ) {
-        case 'GET':
-            drupal_json_output( array( "status" => "error", "info" => "GET requests do nothing; webhooks must be POST, PATCH, PUT, or DELETE" ) );
-            break;
-        case 'DELETE':
-        case 'POST':
-        case 'PATCH':
-        case 'PUT':
-            if ( $payload === null ) {
-                // actually do something :)
-                drupal_json_output( array( 'status' => 'error', 'info' => $payload_error_msg ) );
-            } else {
-                drupal_json_output( array( 'status' => 'ok', 'headers' => $headers, 'method' => $method ) );
+        $client_id = variable_get( 'fulcrm_apiv2_client_id' );
+
+        if ( fulcrm_apiv2_prevent_loop( $headers ) ) {
+            switch ( $method ) {
+            case 'GET':
+                drupal_json_output( array( "status" => "error", "info" => "GET requests do nothing; webhooks must be POST, PATCH, PUT, or DELETE" ) );
+                break;
+            case 'DELETE':
+            case 'POST':
+            case 'PATCH':
+            case 'PUT':
+                if ( $payload === null ) {
+                    drupal_json_output( array( 'status' => 'error', 'info' => $payload_error_msg ) );
+                } else {
+                    // actually do something :)
+                    drupal_json_output( array( 'status' => 'ok', 'headers' => $headers, 'method' => $method ) );
+                }
+                break;
+            default:
+                drupal_json_output( array( 'status' => 'error', 'info' => 'unsupported method' ) );
+                break;
             }
-            break;
-        default:
+        } else {
+            drupal_json_output( array( 'status' => 'ok', 'info' => 'loop prevention' ) );
         }
     } else {
         drupal_access_denied();