diff --git a/src/Model.php b/src/Model.php
index c5685ab..20a8eb5 100644
--- a/src/Model.php
+++ b/src/Model.php
@@ -33,7 +33,9 @@ public function related(string $key, ?string $throughColumn = null): TypedGroupe
         if ($selection instanceof TypedGroupedSelection) {
             return $selection;
         }
-        throw new \InvalidArgumentException();
+        throw new \InvalidArgumentException(
+            'Selection must be a instance of TypedGroupedSelection'
+        );
     }
 
     /**