diff --git a/src/asahi/lib/gen_pack.py b/src/asahi/lib/gen_pack.py
index 5ed28752fc3..c98b0b09637 100644
--- a/src/asahi/lib/gen_pack.py
+++ b/src/asahi/lib/gen_pack.py
@@ -143,6 +143,7 @@ def to_alphanum(name):
         '"': '',
         '+': '',
         '\'': '',
+        '?': '',
     }
 
     for i, j in substitutions.items():