diff --git a/src/matrix/Session.js b/src/matrix/Session.js
index e3f82bda..68afcf5b 100644
--- a/src/matrix/Session.js
+++ b/src/matrix/Session.js
@@ -24,6 +24,7 @@ import {Decryption as OlmDecryption} from "./e2ee/olm/Decryption.js";
 import {Encryption as OlmEncryption} from "./e2ee/olm/Encryption.js";
 import {Decryption as MegOlmDecryption} from "./e2ee/megolm/Decryption.js";
 import {Encryption as MegOlmEncryption} from "./e2ee/megolm/Encryption.js";
+import {MEGOLM_ALGORITHM} from "./e2ee/common.js";
 import {RoomEncryption} from "./e2ee/RoomEncryption.js";
 import {DeviceTracker} from "./e2ee/DeviceTracker.js";
 import {LockMap} from "../utils/LockMap.js";
@@ -108,6 +109,10 @@ export class Session {
         if (!this._olmEncryption) {
             throw new Error("creating room encryption before encryption got globally enabled");
         }
+        // only support megolm
+        if (encryptionParams.algorithm !== MEGOLM_ALGORITHM) {
+            return null;
+        }
         return new RoomEncryption({
             room,
             deviceTracker: this._deviceTracker,
diff --git a/src/matrix/room/Room.js b/src/matrix/room/Room.js
index e8315538..d2272b3d 100644
--- a/src/matrix/room/Room.js
+++ b/src/matrix/room/Room.js
@@ -88,7 +88,9 @@ export class Room extends EventEmitter {
         // encryption got enabled
         if (!this._summary.encryption && summaryChanges.encryption && !this._roomEncryption) {
             this._roomEncryption = this._createRoomEncryption(this, summaryChanges.encryption);
-            this._sendQueue.enableEncryption(this._roomEncryption);
+            if (this._roomEncryption) {
+                this._sendQueue.enableEncryption(this._roomEncryption);
+            }
         }
         if (memberChanges.size) {
             if (this._changedMembersDuringSync) {
@@ -138,7 +140,9 @@ export class Room extends EventEmitter {
             this._summary.load(summary);
             if (this._summary.encryption) {
                 this._roomEncryption = this._createRoomEncryption(this, this._summary.encryption);
-                this._sendQueue.enableEncryption(this._roomEncryption);
+                if (this._roomEncryption) {
+                    this._sendQueue.enableEncryption(this._roomEncryption);
+                }
             }
             // need to load members for name?
             if (this._summary.needsHeroes) {