diff --git a/libraries/AP_InternalError/AP_InternalError.cpp b/libraries/AP_InternalError/AP_InternalError.cpp
index e90a64fb50..52217a3289 100644
--- a/libraries/AP_InternalError/AP_InternalError.cpp
+++ b/libraries/AP_InternalError/AP_InternalError.cpp
@@ -1,15 +1,24 @@
 #include "AP_InternalError.h"
 
+extern const AP_HAL::HAL &hal;
+
 // actually create the instance:
 static AP_InternalError instance;
 
 void AP_InternalError::error(const AP_InternalError::error_t e) {
 #if CONFIG_HAL_BOARD == HAL_BOARD_SITL
-    if (e != AP_InternalError::error_t::watchdog_reset) {
+    switch (e) {
+    case AP_InternalError::error_t::watchdog_reset:
+    case AP_InternalError::error_t::main_loop_stuck:
+        // don't panic on these to facilitate watchdog testing
+        break;
+    default:
         AP_HAL::panic("internal error %u", unsigned(e));
     }
 #endif
     internal_errors |= uint32_t(e);
+    hal.util->persistent_data.internal_errors = internal_errors;
+    hal.util->persistent_data.internal_error_count++;
 }
 
 
diff --git a/libraries/AP_InternalError/AP_InternalError.h b/libraries/AP_InternalError/AP_InternalError.h
index cc46ebe4bc..160ba0526d 100644
--- a/libraries/AP_InternalError/AP_InternalError.h
+++ b/libraries/AP_InternalError/AP_InternalError.h
@@ -48,6 +48,7 @@ public:
         iomcu_reset                 = (1U << 12),
         iomcu_fail                  = (1U << 13),
         spi_fail                    = (1U << 14),
+        main_loop_stuck             = (1U << 15),
     };
 
     void error(const AP_InternalError::error_t error);