1 files changed, 1 insertions, 1 deletions

diff --git a/drivers/avr/ssd1306.h b/drivers/avr/ssd1306.h
index 9669d1b7e..9131afcf6 100644
--- a/drivers/avr/ssd1306.h
+++ b/drivers/avr/ssd1306.h
@@ -66,7 +66,7 @@ struct CharacterMatrix {
     bool     dirty;
 };
 
-struct CharacterMatrix display;
+extern struct CharacterMatrix display;
 
 bool iota_gfx_init(void);
 void iota_gfx_task(void);