diff --git a/firmware/chibios/os/kernel/src/chdebug.c b/firmware/chibios/os/kernel/src/chdebug.c
index 97ee83550e..bc04540d3a 100644
--- a/firmware/chibios/os/kernel/src/chdebug.c
+++ b/firmware/chibios/os/kernel/src/chdebug.c
@@ -154,13 +154,16 @@ void dbg_check_unlock_from_isr(void) {
   dbg_leave_lock();
 }
 
+void firmwareError(const char *fmt, ...);
+
 /**
  * @brief   Guard code for @p CH_IRQ_PROLOGUE().
  *
  * @notapi
  */
 void dbg_check_enter_isr(void) {
-
+  if (dbg_isr_cnt > 2)
+    firmwareError("nesting3");
   port_lock_from_isr();
   if ((dbg_isr_cnt < 0) || (dbg_lock_cnt != 0))
     chDbgPanic("SV#8");