diff --git a/eive_tmtc/tmtc/acs/star_tracker.py b/eive_tmtc/tmtc/acs/star_tracker.py
index 55254f1..80c82d3 100644
--- a/eive_tmtc/tmtc/acs/star_tracker.py
+++ b/eive_tmtc/tmtc/acs/star_tracker.py
@@ -175,7 +175,8 @@ class PartitionSize:
     STAR_TRACKER_FIRMWARE = 464572
 
 
-class Submode:
+class Submode(enum.IntEnum):
+    DEFAULT = 0
     BOOTLOADER = 1
     FIRMWARE = 2