diff --git a/libraries/AP_Networking/lwip_hal/arch/evtimer.c b/libraries/AP_Networking/lwip_hal/arch/evtimer.c
index 53da0413f8..56657904ed 100644
--- a/libraries/AP_Networking/lwip_hal/arch/evtimer.c
+++ b/libraries/AP_Networking/lwip_hal/arch/evtimer.c
@@ -5,6 +5,7 @@
 #include <hal.h>
 
 #if CH_CFG_USE_EVENTS
-#include "../../modules/ChibiOS/os/various/evtimer.c"
+// this include relies on -I for modules/ChibiOS/os/various/cpp_wrappers
+#include <../evtimer.c>
 #endif