diff --git a/matrix_keycloak_bot.py b/matrix_keycloak_bot.py
index f107442..8bcd7ce 100644
--- a/matrix_keycloak_bot.py
+++ b/matrix_keycloak_bot.py
@@ -60,6 +60,27 @@ class CustomMemoryStateStore(MemoryStateStore):
         return shared
 
 
+class CrossSigningKeyWrapper:
+    def __init__(self, key_val):
+        if hasattr(key_val, "key"):
+            self.key = key_val.key
+        elif isinstance(key_val, str):
+            self.key = key_val
+        else:
+            self.key = str(key_val)
+
+    def __str__(self):
+        return self.key
+
+    def __repr__(self):
+        return f"CrossSigningKeyWrapper(key={self.key!r})"
+
+    def __eq__(self, other):
+        if hasattr(other, "key"):
+            return self.key == other.key
+        return self.key == str(other)
+
+
 class CustomMemoryCryptoStore(MemoryCryptoStore):
     def __init__(self, *args, **kwargs):
         super().__init__(*args, **kwargs)
@@ -70,13 +91,19 @@ class CustomMemoryCryptoStore(MemoryCryptoStore):
         usage_str = usage.value if hasattr(usage, "value") else str(usage)
         if user_id not in self._cross_signing_keys:
             self._cross_signing_keys[user_id] = {}
-        self._cross_signing_keys[user_id][usage_str] = key
-        self._cross_signing_keys[user_id][usage] = key
+        wrapped = CrossSigningKeyWrapper(key)
+        self._cross_signing_keys[user_id][usage_str] = wrapped
+        self._cross_signing_keys[user_id][usage] = wrapped
 
     async def get_cross_signing_key(self, user_id: UserID, usage):
         usage_str = usage.value if hasattr(usage, "value") else str(usage)
         user_dict = self._cross_signing_keys.get(user_id, {})
-        return user_dict.get(usage_str) or user_dict.get(usage)
+        val = user_dict.get(usage_str) or user_dict.get(usage)
+        if val is not None and not isinstance(val, CrossSigningKeyWrapper):
+            val = CrossSigningKeyWrapper(val)
+            user_dict[usage_str] = val
+            user_dict[usage] = val
+        return val
 
 
 # ------------------------------------------------------------------------------