diff --git a/src/Illuminate/Support/Reflector.php b/src/Illuminate/Support/Reflector.php
index 3f153bf3bf84..a767d5ea7073 100644
--- a/src/Illuminate/Support/Reflector.php
+++ b/src/Illuminate/Support/Reflector.php
@@ -148,6 +148,10 @@ public static function isParameterSubclassOf($parameter, $className)
      */
     public static function isParameterBackedEnumWithStringBackingType($parameter)
     {
+        if (! $parameter->getType() instanceof ReflectionNamedType) {
+            return false;
+        }
+
         $backedEnumClass = $parameter->getType()?->getName();
 
         if (is_null($backedEnumClass)) {