diff --git a/programs/cmm/lib/keyboard.h b/programs/cmm/lib/keyboard.h
index 16af91ca78..6a1b99bb14 100644
--- a/programs/cmm/lib/keyboard.h
+++ b/programs/cmm/lib/keyboard.h
@@ -37,6 +37,9 @@
 #define SCAN_CODE_PGDN  081
 #define SCAN_CODE_PGUP  073
 
+#define SCAN_CODE_MINUS 012
+#define SCAN_CODE_PLUS  013
+
 #define SCAN_CODE_KEY_C 046
 #define SCAN_CODE_KEY_M 050
 #define SCAN_CODE_KEY_I 023