diff --git a/src/corelib/tools/qelapsedtimer_unix.cpp b/src/corelib/tools/qelapsedtimer_unix.cpp
index c3c930b82e1..27f07d094c1 100644
--- a/src/corelib/tools/qelapsedtimer_unix.cpp
+++ b/src/corelib/tools/qelapsedtimer_unix.cpp
@@ -31,9 +31,6 @@
 **
 ****************************************************************************/
 
-// ask for the latest POSIX, just in case
-#define _POSIX_C_SOURCE 200809L
-
 #include "qelapsedtimer.h"
 #if defined(Q_OS_VXWORKS)
 #include "qfunctions_vxworks.h"