diff --git a/ticket.cpp b/ticket.cpp
index 8e1eca7..1b0b830 100644
--- a/ticket.cpp
+++ b/ticket.cpp
@@ -2,8 +2,9 @@
 
 #include "cmsis_os.h"
 #include "cmsis_version.h"
+#include "main.h"
 extern "C" {
-uint32_t zos_get_tick(void) { return osKernelSysTick(); }
+uint32_t zos_get_tick(void) { return HAL_GetTick(); }
 uint32_t zos_haspassedms2(uint32_t lastticket, uint32_t nowticket) {
   if (nowticket >= lastticket) {
     return nowticket - lastticket;