diff --git a/Tools/AP_Bootloader/mcu_g4.h b/Tools/AP_Bootloader/mcu_g4.h
index 9fcac3c104..a258af137b 100644
--- a/Tools/AP_Bootloader/mcu_g4.h
+++ b/Tools/AP_Bootloader/mcu_g4.h
@@ -7,6 +7,7 @@
 #define STM32_UNKNOWN 0
 
 mcu_des_t mcu_descriptions[] = {
+    { STM32_UNKNOWN,     "STM32G4??",    '?'},
 };
 
 const mcu_rev_t silicon_revs[] = {