diff --git a/source/lib/misc.h b/source/lib/misc.h
index 445c80c475..b1fb71d9ff 100755
--- a/source/lib/misc.h
+++ b/source/lib/misc.h
@@ -38,9 +38,7 @@
 
 #define UNUSED(param) (void)param;
 
-#define ONCE(code) { static bool done; if(!done) { code; }; done = true; }
-
-
+#define ONCE(code) { pthread_mutex_t mutex=PTHREAD_MUTEX_INITIALIZER; if(pthread_mutex_trylock(&(mutex))==0) { code; } }
 
 
 template<bool>