diff --git a/roomserver/internal/helpers/auth.go b/roomserver/internal/helpers/auth.go
index ddda8081c..e4f072a2f 100644
--- a/roomserver/internal/helpers/auth.go
+++ b/roomserver/internal/helpers/auth.go
@@ -20,17 +20,22 @@ import (
 	"sort"
 
 	"github.com/matrix-org/dendrite/roomserver/state"
-	"github.com/matrix-org/dendrite/roomserver/storage"
 	"github.com/matrix-org/dendrite/roomserver/types"
 	"github.com/matrix-org/gomatrixserverlib"
 )
 
+type checkForSoftFailStorage interface {
+	state.StateResolutionStorage
+	StateEntriesForEventIDs(ctx context.Context, eventIDs []string) ([]types.StateEntry, error)
+	RoomInfo(ctx context.Context, roomID string) (*types.RoomInfo, error)
+}
+
 // CheckForSoftFail returns true if the event should be soft-failed
 // and false otherwise. The return error value should be checked before
 // the soft-fail bool.
 func CheckForSoftFail(
 	ctx context.Context,
-	db storage.Database,
+	db checkForSoftFailStorage,
 	event *gomatrixserverlib.HeaderedEvent,
 	stateEventIDs []string,
 ) (bool, error) {
@@ -92,7 +97,7 @@ func CheckForSoftFail(
 // Returns the numeric IDs for the auth events.
 func CheckAuthEvents(
 	ctx context.Context,
-	db storage.Database,
+	db checkForSoftFailStorage,
 	event *gomatrixserverlib.HeaderedEvent,
 	authEventIDs []string,
 ) ([]types.EventNID, error) {
@@ -193,7 +198,7 @@ func (ae *authEvents) lookupEvent(typeNID types.EventTypeNID, stateKey string) *
 // loadAuthEvents loads the events needed for authentication from the supplied room state.
 func loadAuthEvents(
 	ctx context.Context,
-	db storage.Database,
+	db state.StateResolutionStorage,
 	needed gomatrixserverlib.StateNeeded,
 	state []types.StateEntry,
 ) (result authEvents, err error) {
diff --git a/roomserver/internal/input/input_events.go b/roomserver/internal/input/input_events.go
index 3e9a4c414..9ba6dd1ca 100644
--- a/roomserver/internal/input/input_events.go
+++ b/roomserver/internal/input/input_events.go
@@ -204,7 +204,7 @@ func (r *Inputer) processRoomEvent(
 	if input.Kind == api.KindNew {
 		// Check that the event passes authentication checks based on the
 		// current room state.
-		softfail, err = helpers.CheckForSoftFail(ctx, r.DB, headered, input.StateEventIDs)
+		softfail, err = helpers.CheckForSoftFail(ctx, updater, headered, input.StateEventIDs)
 		if err != nil {
 			logger.WithError(err).Warn("Error authing soft-failed event")
 		}