diff --git a/lib/crypto-algorithms/megolm.js b/lib/crypto-algorithms/megolm.js
index b3d5e6ff7..d54a442e6 100644
--- a/lib/crypto-algorithms/megolm.js
+++ b/lib/crypto-algorithms/megolm.js
@@ -184,7 +184,6 @@ MegolmEncryption.prototype.encryptMessage = function(room, eventType, content) {
             sender_key: self._olmDevice.deviceCurve25519Key,
             body: ciphertext,
             session_id: session_id,
-            signature: "FIXME",
         };
 
         return encryptedContent;
@@ -252,7 +251,7 @@ MegolmDecryption.prototype.decryptEvent = function(event) {
                 content.session_id);
 
     if (!content.sender_key || !content.session_id ||
-        !content.body || !content.signature
+        !content.body
        ) {
         throw new base.DecryptionError("Missing fields in input");
     }