diff --git a/cmake/re-config.cmake b/cmake/re-config.cmake
index ba50406ff..a6c8af195 100644
--- a/cmake/re-config.cmake
+++ b/cmake/re-config.cmake
@@ -70,7 +70,9 @@ endif()
 check_function_exists(thrd_create HAVE_THREADS_FUN)
 check_include_file(threads.h HAVE_THREADS_H)
 if(HAVE_THREADS_FUN AND HAVE_THREADS_H)
-  set(HAVE_THREADS true)
+    set(HAVE_THREADS CACHE BOOL true)
+endif()
+if(HAVE_THREADS)
   list(APPEND RE_DEFINITIONS HAVE_THREADS)
 endif()