diff --git a/libraries/AP_Scripting/lua/src/loslib.c b/libraries/AP_Scripting/lua/src/loslib.c
index de590c6b71..9510105778 100644
--- a/libraries/AP_Scripting/lua/src/loslib.c
+++ b/libraries/AP_Scripting/lua/src/loslib.c
@@ -81,7 +81,7 @@ static time_t l_checktime (lua_State *L, int arg) {
 ** where it uses gmtime_r/localtime_r
 */
 
-#if defined(LUA_USE_POSIX)	/* { */
+#if defined(ARDUPILOT_BUILD) || defined(LUA_USE_POSIX)	/* { */
 
 #define l_gmtime(t,r)		gmtime_r(t,r)
 #define l_localtime(t,r)	localtime_r(t,r)