diff --git a/src/Generator/Schema.php b/src/Generator/Schema.php
index d76cb44..325f2e3 100644
--- a/src/Generator/Schema.php
+++ b/src/Generator/Schema.php
@@ -76,7 +76,7 @@ public static function generate(string $name, string $namespace, string $classNa
                 )
             );
             if (is_string($property->type)) {
-                if ($property->type === 'array' && array_key_exists(spl_object_hash($property->items), $schemaClassNameMap)) {
+                if ($property->type === 'array' && $property->items instanceof OpenAPiSchema && array_key_exists(spl_object_hash($property->items), $schemaClassNameMap)) {
                     $docBlock[] = '@var array<' . $namespace . '\\' . $schemaClassNameMap[spl_object_hash($property->items)] . '>';
                 }
                 $propertyStmt->setType(str_replace([