1 files changed, 1 insertions, 1 deletions
diff --git a/shared-bindings/microcontroller/RunMode.h b/shared-bindings/microcontroller/RunMode.h
index 5e8b6e646..ce90ab93a 100644
--- a/shared-bindings/microcontroller/RunMode.h
+++ b/shared-bindings/microcontroller/RunMode.h
@@ -35,7 +35,7 @@ typedef enum {
     RUNMODE_BOOTLOADER
 } mcu_runmode_t;
 
-const mp_obj_type_t mcu_runmode_type;
+extern const mp_obj_type_t mcu_runmode_type;
 
 typedef struct {
     mp_obj_base_t base;