diff --git a/syncapi/storage/shared/syncserver.go b/syncapi/storage/shared/syncserver.go
index 932bda164..cb9789bb8 100644
--- a/syncapi/storage/shared/syncserver.go
+++ b/syncapi/storage/shared/syncserver.go
@@ -765,6 +765,7 @@ func (d *Database) GetStateDeltas(
 		}
 	}
 
+	var membershipPositions = make(map[string]types.StreamPosition)
 	// handle newly joined rooms and non-joined rooms
 	for roomID, stateStreamEvents := range state {
 		for _, ev := range stateStreamEvents {
@@ -784,6 +785,7 @@ func (d *Database) GetStateDeltas(
 						}
 						return nil, nil, err
 					}
+					membershipPositions[roomID] = ev.StreamPosition
 					state[roomID] = s
 					continue // we'll add this room in when we do joined rooms
 				}
@@ -802,9 +804,10 @@ func (d *Database) GetStateDeltas(
 	// Add in currently joined rooms
 	for _, joinedRoomID := range joinedRoomIDs {
 		deltas = append(deltas, types.StateDelta{
-			Membership:  gomatrixserverlib.Join,
-			StateEvents: d.StreamEventsToEvents(device, state[joinedRoomID]),
-			RoomID:      joinedRoomID,
+			Membership:    gomatrixserverlib.Join,
+			MembershipPos: membershipPositions[joinedRoomID],
+			StateEvents:   d.StreamEventsToEvents(device, state[joinedRoomID]),
+			RoomID:        joinedRoomID,
 		})
 	}
 
diff --git a/syncapi/streams/stream_pdu.go b/syncapi/streams/stream_pdu.go
index 00b3dfe3b..2d193f4f2 100644
--- a/syncapi/streams/stream_pdu.go
+++ b/syncapi/streams/stream_pdu.go
@@ -229,6 +229,11 @@ func (p *PDUStreamProvider) addRoomDeltaToResponse(
 		// This is all "okay" assuming history_visibility == "shared" which it is by default.
 		r.To = delta.MembershipPos
 	}
+	// if we joined in between sync calls, send reset From to simulate a complete sync
+	if delta.Membership == gomatrixserverlib.Join && delta.MembershipPos <= r.To && delta.MembershipPos > r.From {
+		r.From = 0
+	}
+
 	recentStreamEvents, limited, err := p.DB.RecentEvents(
 		ctx, delta.RoomID, r,
 		eventFilter, true, true,