diff --git a/syncapi/storage/shared/syncserver.go b/syncapi/storage/shared/syncserver.go
index 90db145e..d8ae455e 100644
--- a/syncapi/storage/shared/syncserver.go
+++ b/syncapi/storage/shared/syncserver.go
@@ -1032,7 +1032,9 @@ func (d *Database) getStateDeltas(
 	}
 
 	// add peek blocks
+	peeking := make(map[string]bool)
 	for _, peek := range peeks {
+		peeking[peek.RoomID] = true
 		if peek.New {
 			// send full room state down instead of a delta
 			var s []types.StreamEvent
@@ -1067,6 +1069,14 @@ func (d *Database) getStateDeltas(
 			//       the timeline.
 			if membership := getMembershipFromEvent(&ev.Event, userID); membership != "" {
 				if membership == gomatrixserverlib.Join {
+					if peeking[roomID] {
+						// we automatically cancel our peeks when we join a room
+						_, err = d.Peeks.DeletePeeks(ctx, txn, roomID, userID)
+						if err != nil {
+							return nil, nil, err
+						}
+					}
+
 					// send full room state down instead of a delta
 					var s []types.StreamEvent
 					s, err = d.currentStateStreamEventsForRoom(ctx, txn, roomID, stateFilter)
diff --git a/syncapi/storage/sqlite3/peeks_table.go b/syncapi/storage/sqlite3/peeks_table.go
index 088f4007..7e8d4c69 100644
--- a/syncapi/storage/sqlite3/peeks_table.go
+++ b/syncapi/storage/sqlite3/peeks_table.go
@@ -48,6 +48,9 @@ const insertPeekSQL = "" +
 const deletePeekSQL = "" +
 	"DELETE FROM syncapi_peeks WHERE room_id = $1 AND user_id = $2 and device_id = $3"
 
+const deletePeeksSQL = "" +
+	"DELETE FROM syncapi_peeks WHERE room_id = $1 AND user_id = $2"
+
 const selectPeeksSQL = "" +
 	"SELECT room_id, new FROM syncapi_peeks WHERE user_id = $1 and device_id = $2"
 
@@ -62,6 +65,7 @@ type peekStatements struct {
 	streamIDStatements            *streamIDStatements
 	insertPeekStmt        		  *sql.Stmt
 	deletePeekStmt         		  *sql.Stmt
+	deletePeeksStmt				  *sql.Stmt
 	selectPeeksStmt				  *sql.Stmt
 	selectPeekingDevicesStmt	  *sql.Stmt
 	markPeeksAsOldStmt            *sql.Stmt
@@ -82,6 +86,9 @@ func NewSqlitePeeksTable(db *sql.DB, streamID *streamIDStatements) (tables.Peeks
 	if s.deletePeekStmt, err = db.Prepare(deletePeekSQL); err != nil {
 		return nil, err
 	}
+	if s.deletePeeksStmt, err = db.Prepare(deletePeeksSQL); err != nil {
+		return nil, err
+	}
 	if s.selectPeeksStmt, err = db.Prepare(selectPeeksSQL); err != nil {
 		return nil, err
 	}
@@ -117,6 +124,17 @@ func (s *peekStatements) DeletePeek(
 	return
 }
 
+func (s *peekStatements) DeletePeeks(
+	ctx context.Context, txn *sql.Tx, roomID, userID string,
+) (streamPos types.StreamPosition, err error) {
+	streamPos, err = s.streamIDStatements.nextStreamID(ctx, txn)
+	if err != nil {
+		return
+	}
+	_, err = sqlutil.TxStmt(txn, s.deletePeeksStmt).ExecContext(ctx, roomID, userID)
+	return
+}
+
 func (s *peekStatements) SelectPeeks(
 	ctx context.Context, txn *sql.Tx, userID, deviceID string,
 ) (peeks []types.Peek, err error) {
diff --git a/syncapi/storage/tables/interface.go b/syncapi/storage/tables/interface.go
index b7281f11..3c6ee4bb 100644
--- a/syncapi/storage/tables/interface.go
+++ b/syncapi/storage/tables/interface.go
@@ -42,6 +42,7 @@ type Invites interface {
 type Peeks interface {
 	InsertPeek(ctx context.Context, txn *sql.Tx, roomID, userID, deviceID string) (streamPos types.StreamPosition, err error)
 	DeletePeek(ctx context.Context, txn *sql.Tx, roomID, userID, deviceID string) (streamPos types.StreamPosition, err error)
+	DeletePeeks(ctx context.Context, txn *sql.Tx, roomID, userID string) (streamPos types.StreamPosition, err error)
 	SelectPeeks(ctxt context.Context, txn *sql.Tx, userID, deviceID string) (peeks []types.Peek, err error)
 	SelectPeekingDevices(ctxt context.Context) (peekingDevices map[string][]types.PeekingDevice, err error)
 	MarkPeeksAsOld(ctxt context.Context, txn *sql.Tx, userID, deviceID string) (err error)
diff --git a/syncapi/sync/notifier.go b/syncapi/sync/notifier.go
index e6f7440e..61300232 100644
--- a/syncapi/sync/notifier.go
+++ b/syncapi/sync/notifier.go
@@ -248,7 +248,7 @@ func (n *Notifier) wakeupUsers(userIDs []string, peekingDevices []types.PeekingD
 	if peekingDevices != nil {
 		for _, peekingDevice := range peekingDevices {
 			// TODO: don't bother waking up for devices whose users we already woke up
-			if stream := n.fetchUserDeviceStream(peekingDevice.UserID, peekingDevice.ID, false); stream != nil {
+			if stream := n.fetchUserDeviceStream(peekingDevice.UserID, peekingDevice.DeviceID, false); stream != nil {
 				stream.Broadcast(newPos) // wake up all goroutines Wait()ing on this stream
 			}
 		}
@@ -337,7 +337,7 @@ func (n *Notifier) addPeekingDevice(roomID, userID, deviceID string) {
 	if _, ok := n.roomIDToPeekingDevices[roomID]; !ok {
 		n.roomIDToPeekingDevices[roomID] = make(peekingDeviceSet)
 	}
-	n.roomIDToPeekingDevices[roomID].add(types.PeekingDevice{deviceID, userID})
+	n.roomIDToPeekingDevices[roomID].add(types.PeekingDevice{userID, deviceID})
 }
 
 // Not thread-safe: must be called on the OnNewEvent goroutine only
@@ -346,7 +346,7 @@ func (n *Notifier) removePeekingDevice(roomID, userID, deviceID string) {
 		n.roomIDToPeekingDevices[roomID] = make(peekingDeviceSet)
 	}
 	// XXX: is this going to work as a key?
-	n.roomIDToPeekingDevices[roomID].remove(types.PeekingDevice{deviceID, userID})
+	n.roomIDToPeekingDevices[roomID].remove(types.PeekingDevice{userID, deviceID})
 }
 
 // Not thread-safe: must be called on the OnNewEvent goroutine only
diff --git a/syncapi/types/types.go b/syncapi/types/types.go
index b9888a65..23d88626 100644
--- a/syncapi/types/types.go
+++ b/syncapi/types/types.go
@@ -511,8 +511,8 @@ type SendToDeviceEvent struct {
 }
 
 type PeekingDevice struct {
-	ID     string
-	UserID string
+	UserID 		string
+	DeviceID    string
 }
 
 type Peek struct {