diff --git a/lib/crypto/index.js b/lib/crypto/index.js
index fbf71f2fb..300e8c56e 100644
--- a/lib/crypto/index.js
+++ b/lib/crypto/index.js
@@ -105,9 +105,6 @@ function Crypto(baseApis, eventEmitter, sessionStore, userId, deviceId) {
     }
 
     _registerEventHandlers(this, eventEmitter);
-
-    // map from userId -> deviceId -> roomId -> timestamp
-    this._lastNewDeviceMessageTsByUserDeviceRoom = {};
 }
 
 function _registerEventHandlers(crypto, eventEmitter) {
@@ -962,58 +959,6 @@ Crypto.prototype.decryptEvent = function(event) {
     alg.decryptEvent(event);
 };
 
-/**
- * Send a "m.new_device" message to remind it that we exist and are a member
- * of a room.
- *
- * This is rate limited to send a message at most once an hour per desination.
- *
- * @param {string}  userId   The ID of the user to ping.
- * @param {string?} deviceId The ID of the device to ping. If null, all
- *     devices.
- * @param {string}  roomId   The ID of the room we want to remind them about.
- */
-Crypto.prototype._sendPingToDevice = function(userId, deviceId, roomId) {
-    if (deviceId === null) {
-        deviceId = "*";
-    }
-
-    var lastMessageTsMap = this._lastNewDeviceMessageTsByUserDeviceRoom;
-
-    var lastTsByDevice = lastMessageTsMap[userId];
-    if (!lastTsByDevice) {
-        lastTsByDevice = lastMessageTsMap[userId] = {};
-    }
-
-    var lastTsByRoom = lastTsByDevice[deviceId];
-    if (!lastTsByRoom) {
-        lastTsByRoom = lastTsByDevice[deviceId] = {};
-    }
-
-    var lastTs = lastTsByRoom[roomId];
-    var timeNowMs = Date.now();
-    var oneHourMs = 1000 * 60 * 60;
-
-    if (lastTs !== undefined && lastTs + oneHourMs > timeNowMs) {
-        // rate-limiting
-        return;
-    }
-
-    var content = {};
-    content[userId] = {};
-    content[userId][deviceId] = {
-        device_id: this._deviceId,
-        rooms: [roomId],
-    };
-
-    this._baseApis.sendToDevice(
-        "m.new_device", // OH HAI!
-        content
-    ).done();
-
-    lastTsByRoom[roomId] = timeNowMs;
-};
-
 /**
  * handle an m.room.encryption event
  *