diff --git a/src/_zkapauthorizer/tests/strategies.py b/src/_zkapauthorizer/tests/strategies.py
index e640b4b65edc74b07926aefe11e681cd410f10ad..130fd307094f8d8d5515f4f4f932d2dd34b4c8a8 100644
--- a/src/_zkapauthorizer/tests/strategies.py
+++ b/src/_zkapauthorizer/tests/strategies.py
@@ -198,6 +198,8 @@ def dummy_ristretto_keys():
         max_size=32,
     ).map(
         b64encode,
+    ).map(
+        lambda bs: bs.decode("ascii"),
     )