diff --git a/lib/crypto-algorithms/megolm.js b/lib/crypto-algorithms/megolm.js
index 9ffa194f9..ef7ab511f 100644
--- a/lib/crypto-algorithms/megolm.js
+++ b/lib/crypto-algorithms/megolm.js
@@ -82,7 +82,7 @@ MegolmEncryption.prototype._ensureOutboundSession = function(room) {
 
     // send the keys to each (unblocked) device in the room.
     var payload = {
-        type: "m.key",
+        type: "m.room_key",
         content: {
             algorithm: olmlib.MEGOLM_ALGORITHM,
             room_id: this._roomId,