diff --git a/rominfo/gameboy_advance.py b/rominfo/gameboy_advance.py
index 469535b..4d9a5e0 100644
--- a/rominfo/gameboy_advance.py
+++ b/rominfo/gameboy_advance.py
@@ -51,7 +51,7 @@ def _gamecode_lookup(code: str) -> str:
             gamecode.append('RTC and solar sensor')
         case 'V':
             gamecode.append('Rumble motor')
-        case '_':
+        case _:
             gamecode.append('Unknown')
 
     match code[3:]:
@@ -69,7 +69,7 @@ def _gamecode_lookup(code: str) -> str:
             gamecode.append('Europe/elsewhere')
         case 'S':
             gamecode.append('Spanish')
-        case '_':
+        case _:
             gamecode.append('Unknown')
 
     return '{} ({})'.format(code, f'Type: {gamecode[0]} | Language: {gamecode[1]})')