diff --git a/synapse/handlers/e2e_room_keys.py b/synapse/handlers/e2e_room_keys.py
index 9e40ee7961..ea604584e6 100644
--- a/synapse/handlers/e2e_room_keys.py
+++ b/synapse/handlers/e2e_room_keys.py
@@ -100,6 +100,8 @@ class E2eRoomKeysHandler(object):
                 rooms
             session_id(string): session ID to delete keys for, for None to delete keys
                 for all sessions
+        Raises:
+            NotFoundError: if the backup version does not exist
         Returns:
             A dict containing the count and hash for the backup version
         """
@@ -216,7 +218,7 @@ class E2eRoomKeysHandler(object):
             if changed:
                 version_hash = version_hash + 1
                 yield self.store.update_e2e_room_keys_version(
-                    user_id, version, {"hash": str(version_hash)}
+                    user_id, version, None, version_hash
                 )
 
             count = yield self.store.count_e2e_room_keys(user_id, version)
@@ -366,10 +368,6 @@ class E2eRoomKeysHandler(object):
             if old_info["algorithm"] != version_info["algorithm"]:
                 raise SynapseError(400, "Algorithm does not match", Codes.INVALID_PARAM)
 
-            # don't allow the user to set the hash
-            if "hash" in version_info:
-                del version_info["hash"]
-
             yield self.store.update_e2e_room_keys_version(
                 user_id, version, version_info
             )
diff --git a/synapse/storage/e2e_room_keys.py b/synapse/storage/e2e_room_keys.py
index a10ee71fe7..94a6a7300c 100644
--- a/synapse/storage/e2e_room_keys.py
+++ b/synapse/storage/e2e_room_keys.py
@@ -169,7 +169,7 @@ class EndToEndRoomKeyStore(SQLBaseStore):
 
     @staticmethod
     def _get_e2e_room_keys_multi_txn(txn, user_id, version, room_keys):
-        if not len(room_keys):
+        if not room_keys:
             return {}
 
         where_clauses = []
@@ -185,6 +185,10 @@ class EndToEndRoomKeyStore(SQLBaseStore):
                 % (",".join(["?" for _ in sessions]),)
             )
 
+        # check if we're actually querying something
+        if not where_clauses:
+            return {}
+
         sql = """
         SELECT room_id, session_id, first_message_index, forwarded_count,
                is_verified, session_data
@@ -282,6 +286,7 @@ class EndToEndRoomKeyStore(SQLBaseStore):
                 version(str)
                 algorithm(str)
                 auth_data(object): opaque dict supplied by the client
+                hash(int): tag of the keys in the backup
         """
 
         def _get_e2e_room_keys_version_info_txn(txn):
@@ -351,27 +356,29 @@ class EndToEndRoomKeyStore(SQLBaseStore):
             "create_e2e_room_keys_version_txn", _create_e2e_room_keys_version_txn
         )
 
-    def update_e2e_room_keys_version(self, user_id, version, info):
+    def update_e2e_room_keys_version(self, user_id, version, info=None, version_hash=None):
         """Update a given backup version
 
         Args:
             user_id(str): the user whose backup version we're updating
             version(str): the version ID of the backup version we're updating
             info(dict): the new backup version info to store
+            version_hash(str): tag of the keys in the backup
         """
         updatevalues = {}
 
-        if "auth_data" in info:
+        if info and "auth_data" in info:
             updatevalues["auth_data"] = json.dumps(info["auth_data"])
-        if "hash" in info:
-            updatevalues["hash"] = info["hash"]
+        if version_hash:
+            updatevalues["hash"] = version_hash
 
-        return self._simple_update(
-            table="e2e_room_keys_versions",
-            keyvalues={"user_id": user_id, "version": version},
-            updatevalues=updatevalues,
-            desc="update_e2e_room_keys_version",
-        )
+        if updatevalues:
+            return self._simple_update(
+                table="e2e_room_keys_versions",
+                keyvalues={"user_id": user_id, "version": version},
+                updatevalues=updatevalues,
+                desc="update_e2e_room_keys_version",
+            )
 
     def delete_e2e_room_keys_version(self, user_id, version=None):
         """Delete a given backup version of the user's room keys.