diff --git a/src/chvt.c b/src/chvt.c
index 5c08bfa5e..f086044a2 100644
--- a/src/chvt.c
+++ b/src/chvt.c
@@ -80,7 +80,7 @@ void chVTResetI(VirtualTimer *vtp) {
     vtp->vt_next->vt_time += vtp->vt_time;
   vtp->vt_prev->vt_next = vtp->vt_next;
   vtp->vt_next->vt_prev = vtp->vt_prev;
-  vtp->vt_func = 0;
+  vtp->vt_func = NULL;
 }
 
 /**