diff --git a/src/corelib/kernel/qtimerinfo_unix_p.h b/src/corelib/kernel/qtimerinfo_unix_p.h
index 3d80c929e3..902450dee9 100644
--- a/src/corelib/kernel/qtimerinfo_unix_p.h
+++ b/src/corelib/kernel/qtimerinfo_unix_p.h
@@ -15,6 +15,8 @@
 // We mean it.
 //
 
+#include "qplatformdefs.h" // _POSIX_MONOTONIC_CLOCK-0
+
 #include <QtCore/private/qglobal_p.h>
 
 // #define QTIMERINFO_DEBUG