diff --git a/synapse/storage/_base.py b/synapse/storage/_base.py
index 1e27c2c0c..e0d709869 100644
--- a/synapse/storage/_base.py
+++ b/synapse/storage/_base.py
@@ -453,7 +453,9 @@ class SQLBaseStore(object):
             keyvalues (dict): The unique key tables and their new values
             values (dict): The nonunique columns and their new values
             insertion_values (dict): key/values to use when inserting
-        Returns: A deferred
+        Returns:
+            Deferred(bool): True if a new entry was created, False if an
+                existing one was updated.
         """
         return self.runInteraction(
             desc,
@@ -498,6 +500,10 @@ class SQLBaseStore(object):
             )
             txn.execute(sql, allvalues.values())
 
+            return True
+        else:
+            return False
+
     def _simple_select_one(self, table, keyvalues, retcols,
                            allow_none=False, desc="_simple_select_one"):
         """Executes a SELECT query on the named table, which is expected to
diff --git a/synapse/storage/pusher.py b/synapse/storage/pusher.py
index d9afd7ec8..9e8e2e296 100644
--- a/synapse/storage/pusher.py
+++ b/synapse/storage/pusher.py
@@ -156,8 +156,7 @@ class PusherStore(SQLBaseStore):
                    profile_tag=""):
         with self._pushers_id_gen.get_next() as stream_id:
             def f(txn):
-                txn.call_after(self.get_users_with_pushers_in_room.invalidate_all)
-                return self._simple_upsert_txn(
+                newly_inserted = self._simple_upsert_txn(
                     txn,
                     "pushers",
                     {
@@ -178,11 +177,18 @@ class PusherStore(SQLBaseStore):
                         "id": stream_id,
                     },
                 )
-        defer.returnValue((yield self.runInteraction("add_pusher", f)))
+                if newly_inserted:
+                    # get_users_with_pushers_in_room only cares if the user has
+                    # at least *one* pusher.
+                    txn.call_after(self.get_users_with_pushers_in_room.invalidate_all)
+
+            yield self.runInteraction("add_pusher", f)
 
     @defer.inlineCallbacks
     def delete_pusher_by_app_id_pushkey_user_id(self, app_id, pushkey, user_id):
         def delete_pusher_txn(txn, stream_id):
+            txn.call_after(self.get_users_with_pushers_in_room.invalidate_all)
+
             self._simple_delete_one_txn(
                 txn,
                 "pushers",
@@ -194,6 +200,7 @@ class PusherStore(SQLBaseStore):
                 {"app_id": app_id, "pushkey": pushkey, "user_id": user_id},
                 {"stream_id": stream_id},
             )
+
         with self._pushers_id_gen.get_next() as stream_id:
             yield self.runInteraction(
                 "delete_pusher", delete_pusher_txn, stream_id