diff --git a/roomserver/internal/perform/perform_create_room.go b/roomserver/internal/perform/perform_create_room.go
index fd8055e09..dcaf8dca6 100644
--- a/roomserver/internal/perform/perform_create_room.go
+++ b/roomserver/internal/perform/perform_create_room.go
@@ -16,6 +16,7 @@ package perform
 
 import (
 	"context"
+	"crypto/ed25519"
 	"encoding/json"
 	"fmt"
 	"net/http"
@@ -74,7 +75,7 @@ func (c *Creator) PerformCreateRoom(ctx context.Context, userID spec.UserID, roo
 				JSON: spec.InternalServerError{},
 			}
 		}
-		senderID = spec.SenderID(spec.Base64Bytes(key).Encode())
+		senderID = spec.SenderID(spec.Base64Bytes(key.Public().(ed25519.PublicKey)).Encode())
 	} else {
 		senderID = spec.SenderID(userID.String())
 	}
diff --git a/roomserver/storage/postgres/user_room_keys_table.go b/roomserver/storage/postgres/user_room_keys_table.go
index dbb4af34a..dd4d9ab13 100644
--- a/roomserver/storage/postgres/user_room_keys_table.go
+++ b/roomserver/storage/postgres/user_room_keys_table.go
@@ -145,7 +145,7 @@ func (s *userRoomKeysStatements) BulkSelectUserNIDs(ctx context.Context, txn *sq
 		if err = rows.Scan(&userRoomKeyPair.EventStateKeyNID, &userRoomKeyPair.RoomNID, &publicKey); err != nil {
 			return nil, err
 		}
-		result[string(publicKey)] = userRoomKeyPair
+		result[spec.Base64Bytes(publicKey).Encode()] = userRoomKeyPair
 	}
 	return result, rows.Err()
 }
diff --git a/roomserver/storage/sqlite3/user_room_keys_table.go b/roomserver/storage/sqlite3/user_room_keys_table.go
index 84c8b54ec..d58b8ac3f 100644
--- a/roomserver/storage/sqlite3/user_room_keys_table.go
+++ b/roomserver/storage/sqlite3/user_room_keys_table.go
@@ -25,6 +25,7 @@ import (
 	"github.com/matrix-org/dendrite/internal/sqlutil"
 	"github.com/matrix-org/dendrite/roomserver/storage/tables"
 	"github.com/matrix-org/dendrite/roomserver/types"
+	"github.com/matrix-org/gomatrixserverlib/spec"
 )
 
 const userRoomKeysSchema = `
@@ -159,7 +160,7 @@ func (s *userRoomKeysStatements) BulkSelectUserNIDs(ctx context.Context, txn *sq
 		if err = rows.Scan(&userRoomKeyPair.EventStateKeyNID, &userRoomKeyPair.RoomNID, &publicKey); err != nil {
 			return nil, err
 		}
-		result[string(publicKey)] = userRoomKeyPair
+		result[spec.Base64Bytes(publicKey).Encode()] = userRoomKeyPair
 	}
 	return result, rows.Err()
 }