diff --git a/core/frontend.py b/core/frontend.py
index 2e2fc2d..8226759 100644
--- a/core/frontend.py
+++ b/core/frontend.py
@@ -21,6 +21,10 @@ from os import path, environ, mkdir, W_OK, access
 from core import CoreConfig, Utils
 from core.data import Data
 
+# A-HJ-NP-Z
+SERIAL_LETTERS = ['A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'J', 'K', 'L', 'M', 'N', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z']
+ARTEMIS_SERIAL_PREFIX = "A69A"
+
 class PermissionOffset(Enum):
     USER = 0 # Regular user
     USERMOD = 1 # Can moderate other users
@@ -892,8 +896,13 @@ class FE_System(FE_Base):
             generated = await self.data.arcade.get_num_generated_keychips()
             if not generated:
                 generated = 0
-            serial = self.data.arcade.format_serial("A69A", 1, "A", generated + 1, int(append))
-            serial_dash = self.data.arcade.format_serial("A69A", 1, "A", generated + 1, int(append), True)
+            
+            rollover = generated // 9999
+            serial_num = (generated % 9999) + 1
+            serial_letter = SERIAL_LETTERS[rollover]
+
+            serial_dash = self.data.arcade.format_serial(ARTEMIS_SERIAL_PREFIX, 1, serial_letter, serial_num, int(append), True)
+            serial = serial_dash.replace("-", "")
         
         cab_id = await self.data.arcade.create_machine(int(shopid), serial, None, game_code if game_code else None)