diff --git a/syncapi/storage/sqlite3/current_room_state_table.go b/syncapi/storage/sqlite3/current_room_state_table.go
index 5d81547eb..55ed27a41 100644
--- a/syncapi/storage/sqlite3/current_room_state_table.go
+++ b/syncapi/storage/sqlite3/current_room_state_table.go
@@ -186,7 +186,7 @@ func (s *currentRoomStateStatements) SelectCurrentState(
 		},
 		stateFilter.Senders, stateFilter.NotSenders,
 		stateFilter.Types, stateFilter.NotTypes,
-		stateFilter.Limit, "",
+		stateFilter.Limit, FilterOrderNone,
 	)
 	if err != nil {
 		return nil, fmt.Errorf("s.prepareWithFilters: %w", err)
diff --git a/syncapi/storage/sqlite3/filtering.go b/syncapi/storage/sqlite3/filtering.go
index 0f6bd681f..0faf5297a 100644
--- a/syncapi/storage/sqlite3/filtering.go
+++ b/syncapi/storage/sqlite3/filtering.go
@@ -7,6 +7,14 @@ import (
 	"github.com/matrix-org/dendrite/internal/sqlutil"
 )
 
+type FilterOrder int
+
+const (
+	FilterOrderNone = iota
+	FilterOrderAsc
+	FilterOrderDesc
+)
+
 // prepareWithFilters returns a prepared statement with the
 // relevant filters included. It also includes an []interface{}
 // list of all the relevant parameters to pass straight to
@@ -18,7 +26,7 @@ import (
 func prepareWithFilters(
 	db *sql.DB, txn *sql.Tx, query string, params []interface{},
 	senders, notsenders, types, nottypes []string,
-	limit int, order string,
+	limit int, order FilterOrder,
 ) (*sql.Stmt, []interface{}, error) {
 	offset := len(params)
 	if count := len(senders); count > 0 {
@@ -45,8 +53,11 @@ func prepareWithFilters(
 			params, offset = append(params, v), offset+1
 		}
 	}
-	if order != "" {
-		query += " ORDER BY id " + order
+	switch order {
+	case FilterOrderAsc:
+		query += " ORDER BY id ASC"
+	case FilterOrderDesc:
+		query += " ORDER BY id DESC"
 	}
 	query += fmt.Sprintf(" LIMIT $%d", offset+1)
 	params = append(params, limit)
diff --git a/syncapi/storage/sqlite3/output_room_events_table.go b/syncapi/storage/sqlite3/output_room_events_table.go
index 4debc53f6..019aba8b3 100644
--- a/syncapi/storage/sqlite3/output_room_events_table.go
+++ b/syncapi/storage/sqlite3/output_room_events_table.go
@@ -150,7 +150,7 @@ func (s *outputRoomEventsStatements) SelectStateInRange(
 		},
 		stateFilter.Senders, stateFilter.NotSenders,
 		stateFilter.Types, stateFilter.NotTypes,
-		stateFilter.Limit, "ASC",
+		stateFilter.Limit, FilterOrderAsc,
 	)
 	if err != nil {
 		return nil, nil, fmt.Errorf("s.prepareWithFilters: %w", err)
@@ -273,11 +273,14 @@ func (s *outputRoomEventsStatements) InsertEvent(
 	if len(addState) > 0 {
 		addStateJSON, err = json.Marshal(addState)
 	}
+	if err != nil {
+		return 0, fmt.Errorf("json.Marshal(addState): %w", err)
+	}
 	if len(removeState) > 0 {
 		removeStateJSON, err = json.Marshal(removeState)
 	}
 	if err != nil {
-		return 0, err
+		return 0, fmt.Errorf("json.Marshal(removeState): %w", err)
 	}
 
 	streamPos, err := s.streamIDStatements.nextPDUID(ctx, txn)
@@ -323,7 +326,7 @@ func (s *outputRoomEventsStatements) SelectRecentEvents(
 		},
 		eventFilter.Senders, eventFilter.NotSenders,
 		eventFilter.Types, eventFilter.NotTypes,
-		eventFilter.Limit+1, "DESC",
+		eventFilter.Limit+1, FilterOrderDesc,
 	)
 	if err != nil {
 		return nil, false, fmt.Errorf("s.prepareWithFilters: %w", err)
@@ -371,7 +374,7 @@ func (s *outputRoomEventsStatements) SelectEarlyEvents(
 		},
 		eventFilter.Senders, eventFilter.NotSenders,
 		eventFilter.Types, eventFilter.NotTypes,
-		eventFilter.Limit, "ASC",
+		eventFilter.Limit, FilterOrderAsc,
 	)
 	if err != nil {
 		return nil, fmt.Errorf("s.prepareWithFilters: %w", err)
diff --git a/syncapi/sync/request.go b/syncapi/sync/request.go
index 58eb531c0..09a62e3dd 100644
--- a/syncapi/sync/request.go
+++ b/syncapi/sync/request.go
@@ -49,21 +49,22 @@ func newSyncRequest(req *http.Request, device userapi.Device, syncDB storage.Dat
 	filterQuery := req.URL.Query().Get("filter")
 	if filterQuery != "" {
 		if filterQuery[0] == '{' {
-			// attempt to parse the timeline limit at least
+			// Parse the filter from the query string
 			if err := json.Unmarshal([]byte(filterQuery), &filter); err != nil {
 				return nil, fmt.Errorf("json.Unmarshal: %w", err)
 			}
 		} else {
-			// attempt to load the filter ID
+			// Try to load the filter from the database
 			localpart, _, err := gomatrixserverlib.SplitID('@', device.UserID)
 			if err != nil {
 				util.GetLogger(req.Context()).WithError(err).Error("gomatrixserverlib.SplitID failed")
-				return nil, err
+				return nil, fmt.Errorf("gomatrixserverlib.SplitID: %w", err)
 			}
-			if f, err := syncDB.GetFilter(req.Context(), localpart, filterQuery); err == nil {
-				filter = *f
+			if f, err := syncDB.GetFilter(req.Context(), localpart, filterQuery); err != nil {
+				util.GetLogger(req.Context()).WithError(err).Error("syncDB.GetFilter failed")
+				return nil, fmt.Errorf("syncDB.GetFilter: %w", err)
 			} else {
-				panic(err)
+				filter = *f
 			}
 		}
 	}