diff --git a/src/MeoAssistant/Controller.cpp b/src/MeoAssistant/Controller.cpp
index 5e5f80a747..9c0b41bf56 100644
--- a/src/MeoAssistant/Controller.cpp
+++ b/src/MeoAssistant/Controller.cpp
@@ -30,7 +30,7 @@ asst::Controller::Controller()
 
 #ifdef _WIN32
     // 安全属性描述符
-    m_pipe_sec_attr.nLength = sizeof SECURITY_ATTRIBUTES;
+    m_pipe_sec_attr.nLength = sizeof(SECURITY_ATTRIBUTES);
     m_pipe_sec_attr.lpSecurityDescriptor = nullptr;
     m_pipe_sec_attr.bInheritHandle = TRUE;