diff --git a/pymake/cmake.py b/pymake/cmake.py
index ae467f3..9589542 100644
--- a/pymake/cmake.py
+++ b/pymake/cmake.py
@@ -58,6 +58,6 @@ class cmake:
         self.__write_stack__.append(f"file({mode} {new_var_name} {args_to_str(search_str)})")
         return self
     
-    def add_subdirectory(self,path:str)->'cmake':
+    def add_subdirectory(self,path:str)->Self:
         self.__write_stack__.append(f"add_subdirectory({path})")
         return self
\ No newline at end of file