diff --git a/websocketpp/common/regex.hpp b/websocketpp/common/regex.hpp
index 0beb2bbaa1..ddc5e582c3 100644
--- a/websocketpp/common/regex.hpp
+++ b/websocketpp/common/regex.hpp
@@ -28,7 +28,7 @@
 #ifndef WEBSOCKETPP_COMMON_REGEX_HPP
 #define WEBSOCKETPP_COMMON_REGEX_HPP
 
-#ifdef _WEBSOCKETPP_CPP11_STL_
+#if defined _WEBSOCKETPP_CPP11_STL_ && !defined _WEBSOCKETPP_NO_CPP11_REGEX_
 	#ifndef _WEBSOCKETPP_CPP11_REGEX_
 		#define _WEBSOCKETPP_CPP11_REGEX_
 	#endif