diff --git a/lib/client.js b/lib/client.js
index a2eff6fa1..7c6a2ddb0 100644
--- a/lib/client.js
+++ b/lib/client.js
@@ -662,6 +662,12 @@ function _sendEncryptedMessage(client, roomId, e2eRoomInfo, eventType, content,
 }
 
 function _decryptMessage(client, event) {
+    if (client.sessionStore === null) {
+        // End to end encryption isn't enabled if we don't have a session
+        // store.
+        return _badEncryptedMessage(event, "Encryption not enabled");
+    }
+
     var content = event.getContent();
     if (content.algorithm === OLM_ALGORITHM) {
         var sender = event.getSender();
@@ -726,12 +732,12 @@ function _decryptMessage(client, event) {
                 user_id: event.getSender()
             });
         } else {
-            return _badEncryptedMessge(event, "Bad Encrypted Message");
+            return _badEncryptedMessage(event, "Bad Encrypted Message");
         }
     }
 }
 
-function _badEncryptedMessge(event, reason) {
+function _badEncryptedMessage(event, reason) {
     return new MatrixEvent({
         type: "m.room.message",
         // TODO: Add rest of the event keys.