diff --git a/include/pocketpy/io.h b/include/pocketpy/io.h
index 825094d7..76806cad 100644
--- a/include/pocketpy/io.h
+++ b/include/pocketpy/io.h
@@ -28,4 +28,5 @@ struct FileIO {
     static void _register(VM* vm, PyObject* mod, PyObject* type);
 };
 
+} // namespace pkpy
 #endif
\ No newline at end of file