diff --git a/src/Writing/Writer.php b/src/Writing/Writer.php
index 8c350018..1214f1fd 100644
--- a/src/Writing/Writer.php
+++ b/src/Writing/Writer.php
@@ -142,7 +142,7 @@ public function generateOpenAPISpec(array $groupedEndpoints): string
         /** @var OpenAPISpecWriter $writer */
         $writer = app()->makeWith(OpenAPISpecWriter::class, ['config' => $this->config]);
         $spec = $writer->generateSpecContent($groupedEndpoints);
-        return Yaml::dump($spec, 20, 2, Yaml::DUMP_EMPTY_ARRAY_AS_SEQUENCE | Yaml::DUMP_OBJECT_AS_MAP);
+        return Yaml::dump($spec, 20, 2, Yaml::DUMP_EMPTY_ARRAY_AS_SEQUENCE | Yaml::DUMP_OBJECT_AS_MAP | Yaml::DUMP_NUMERIC_KEY_AS_STRING);
     }
 
     protected function performFinalTasksForLaravelType(): void