diff --git a/CMakeLists.txt b/CMakeLists.txt
index 4c63490..65fde9e 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -61,7 +61,7 @@ execute_process (
     ERROR_QUIET
 )
 if (NOT STATUS_CXX11_THREADS EQUAL 0)
-    message (SEND_ERROR "Win32 threads required.")
+    message (WARNING "Win32 threads required.")
 endif ()
 
 # Enable stack protection
