diff --git a/lib/server/swarm.js b/lib/server/swarm.js
index 62e406f..8d2765c 100644
--- a/lib/server/swarm.js
+++ b/lib/server/swarm.js
@@ -4,7 +4,7 @@ var debug = require('debug')('bittorrent-tracker')
 var randomIterate = require('random-iterate')
 
 // Regard this as the default implementation of an interface that you
-// need to support when overriding Server.getSwarm()
+// need to support when overriding Server.createSwarm() and Server.getSwarm()
 function Swarm (infoHash, server) {
   this.peers = {}
   this.complete = 0
diff --git a/server.js b/server.js
index bbb58b0..ba8aff5 100644
--- a/server.js
+++ b/server.js
@@ -196,17 +196,23 @@ Server.prototype.close = function (cb) {
   else cb(null)
 }
 
-Server.prototype.createSwarm = function (infoHash) {
+Server.prototype.createSwarm = function (infoHash, cb) {
   var self = this
   if (Buffer.isBuffer(infoHash)) infoHash = infoHash.toString('hex')
-  var swarm = self.torrents[infoHash] = new Swarm(infoHash, self)
-  return swarm
+
+  process.nextTick(function () {
+    var swarm = self.torrents[infoHash] = new Swarm(infoHash, self)
+    cb(null, swarm)
+  })
 }
 
-Server.prototype.getSwarm = function (infoHash) {
+Server.prototype.getSwarm = function (infoHash, cb) {
   var self = this
   if (Buffer.isBuffer(infoHash)) infoHash = infoHash.toString('hex')
-  return self.torrents[infoHash]
+
+  process.nextTick(function () {
+    cb(null, self.torrents[infoHash])
+  })
 }
 
 Server.prototype.onHttpRequest = function (req, res, opts) {
@@ -358,26 +364,35 @@ Server.prototype._onWebSocketRequest = function (socket, params) {
     if (params.answer) {
       debug('got answer %s from %s', JSON.stringify(params.answer), params.peer_id)
 
-      var swarm = self.getSwarm(params.info_hash)
-      if (!swarm) {
-        return self.emit('warning', new Error('no swarm with that `info_hash`'))
-      }
-      var toPeer = swarm.peers[params.to_peer_id]
-      if (!toPeer) {
-        return self.emit('warning', new Error('no peer with that `to_peer_id`'))
-      }
+      self.getSwarm(params.info_hash, function (err, swarm) {
+        if (err) return self.emit('warning', err)
+        if (!swarm) {
+          return self.emit('warning', new Error('no swarm with that `info_hash`'))
+        }
+        var toPeer = swarm.peers[params.to_peer_id]
+        if (!toPeer) {
+          return self.emit('warning', new Error('no peer with that `to_peer_id`'))
+        }
 
-      toPeer.socket.send(JSON.stringify({
-        answer: params.answer,
-        offer_id: params.offer_id,
-        peer_id: common.hexToBinary(params.peer_id),
-        info_hash: common.hexToBinary(params.info_hash)
-      }), toPeer.socket.onSend)
-      debug('sent answer to %s from %s', toPeer.peerId, params.peer_id)
+        toPeer.socket.send(JSON.stringify({
+          answer: params.answer,
+          offer_id: params.offer_id,
+          peer_id: common.hexToBinary(params.peer_id),
+          info_hash: common.hexToBinary(params.info_hash)
+        }), toPeer.socket.onSend)
+        debug('sent answer to %s from %s', toPeer.peerId, params.peer_id)
+
+        done()
+      })
+    } else {
+      done()
     }
 
-    if (params.action === common.ACTIONS.ANNOUNCE) {
-      self.emit(common.EVENT_NAMES[params.event], params.peer_id, params)
+    function done () {
+      // emit event once the announce is fully "processed"
+      if (params.action === common.ACTIONS.ANNOUNCE) {
+        self.emit(common.EVENT_NAMES[params.event], params.peer_id, params)
+      }
     }
   })
 }
@@ -398,9 +413,14 @@ Server.prototype._onRequest = function (params, cb) {
 Server.prototype._onAnnounce = function (params, cb) {
   var self = this
 
-  var swarm = self.getSwarm(params.info_hash)
-  if (swarm) announce()
-  else createSwarm()
+  self.getSwarm(params.info_hash, function (err, swarm) {
+    if (err) return cb(err)
+    if (swarm) {
+      announce(swarm)
+    } else {
+      createSwarm()
+    }
+  })
 
   function createSwarm () {
     if (self._filter) {
@@ -410,17 +430,21 @@ Server.prototype._onAnnounce = function (params, cb) {
         } else if (!allowed) {
           cb(new Error('disallowed info_hash'))
         } else {
-          swarm = self.createSwarm(params.info_hash)
-          announce()
+          self.createSwarm(params.info_hash, function (err, swarm) {
+            if (err) return cb(err)
+            announce(swarm)
+          })
         }
       })
     } else {
-      swarm = self.createSwarm(params.info_hash)
-      announce()
+      self.createSwarm(params.info_hash, function (err, swarm) {
+        if (err) return cb(err)
+        announce(swarm)
+      })
     }
   }
 
-  function announce () {
+  function announce (swarm) {
     if (!params.event || params.event === 'empty') params.event = 'update'
     swarm.announce(params, function (err, response) {
       if (err) return cb(err)
@@ -470,19 +494,21 @@ Server.prototype._onScrape = function (params, cb) {
 
   series(params.info_hash.map(function (infoHash) {
     return function (cb) {
-      var swarm = self.getSwarm(infoHash)
-      if (swarm) {
-        swarm.scrape(params, function (err, scrapeInfo) {
-          if (err) return cb(err)
-          cb(null, {
-            infoHash: infoHash,
-            complete: (scrapeInfo && scrapeInfo.complete) || 0,
-            incomplete: (scrapeInfo && scrapeInfo.incomplete) || 0
+      self.getSwarm(infoHash, function (err, swarm) {
+        if (err) return cb(err)
+        if (swarm) {
+          swarm.scrape(params, function (err, scrapeInfo) {
+            if (err) return cb(err)
+            cb(null, {
+              infoHash: infoHash,
+              complete: (scrapeInfo && scrapeInfo.complete) || 0,
+              incomplete: (scrapeInfo && scrapeInfo.incomplete) || 0
+            })
           })
-        })
-      } else {
-        cb(null, { infoHash: infoHash, complete: 0, incomplete: 0 })
-      }
+        } else {
+          cb(null, { infoHash: infoHash, complete: 0, incomplete: 0 })
+        }
+      })
     }
   }), function (err, results) {
     if (err) return cb(err)
diff --git a/test/server.js b/test/server.js
index 91e6057..4a0d177 100644
--- a/test/server.js
+++ b/test/server.js
@@ -8,7 +8,7 @@ var peerId2 = new Buffer('12345678901234567890')
 var torrentLength = 50000
 
 function serverTest (t, serverType, serverFamily) {
-  t.plan(25)
+  t.plan(26)
 
   var opts = serverType === 'http' ? { udp: false, ws: false } : { http: false, ws: false }
   var server = new Server(opts)
@@ -49,65 +49,67 @@ function serverTest (t, serverType, serverFamily) {
       t.equal(data.complete, 0)
       t.equal(data.incomplete, 1)
 
-      var swarm = server.getSwarm(infoHash)
+      server.getSwarm(infoHash, function (err, swarm) {
+        t.error(err)
 
-      t.equal(Object.keys(server.torrents).length, 1)
-      t.equal(swarm.complete, 0)
-      t.equal(swarm.incomplete, 1)
-      t.equal(Object.keys(swarm.peers).length, 1)
-      t.deepEqual(swarm.peers[clientAddr + ':6881'], {
-        ip: clientIp,
-        port: 6881,
-        peerId: peerId.toString('hex'),
-        complete: false,
-        socket: undefined
-      })
+        t.equal(Object.keys(server.torrents).length, 1)
+        t.equal(swarm.complete, 0)
+        t.equal(swarm.incomplete, 1)
+        t.equal(Object.keys(swarm.peers).length, 1)
+        t.deepEqual(swarm.peers[clientAddr + ':6881'], {
+          ip: clientIp,
+          port: 6881,
+          peerId: peerId.toString('hex'),
+          complete: false,
+          socket: undefined
+        })
 
-      client1.complete()
+        client1.complete()
 
-      client1.once('update', function (data) {
-        t.equal(data.announce, announceUrl)
-        t.equal(data.complete, 1)
-        t.equal(data.incomplete, 0)
-
-        client1.scrape()
-
-        client1.once('scrape', function (data) {
+        client1.once('update', function (data) {
           t.equal(data.announce, announceUrl)
-          t.equal(typeof data.complete, 'number')
-          t.equal(typeof data.incomplete, 'number')
-          t.equal(typeof data.downloaded, 'number')
+          t.equal(data.complete, 1)
+          t.equal(data.incomplete, 0)
 
-          var client2 = new Client(peerId2, 6882, {
-            infoHash: infoHash,
-            length: torrentLength,
-            announce: [ announceUrl ]
-          })
+          client1.scrape()
 
-          client2.start()
+          client1.once('scrape', function (data) {
+            t.equal(data.announce, announceUrl)
+            t.equal(typeof data.complete, 'number')
+            t.equal(typeof data.incomplete, 'number')
+            t.equal(typeof data.downloaded, 'number')
 
-          server.once('start', function () {
-            t.pass('got start message from client2')
-          })
+            var client2 = new Client(peerId2, 6882, {
+              infoHash: infoHash,
+              length: torrentLength,
+              announce: [ announceUrl ]
+            })
 
-          client2.once('peer', function (addr) {
-            t.ok(addr === clientAddr + ':6881' || addr === clientAddr + ':6882')
+            client2.start()
 
-            client2.stop()
-            client2.once('update', function (data) {
-              t.equal(data.announce, announceUrl)
-              t.equal(data.complete, 1)
-              t.equal(data.incomplete, 0)
-              client2.destroy()
+            server.once('start', function () {
+              t.pass('got start message from client2')
+            })
 
-              client1.stop()
-              client1.once('update', function (data) {
+            client2.once('peer', function (addr) {
+              t.ok(addr === clientAddr + ':6881' || addr === clientAddr + ':6882')
+
+              client2.stop()
+              client2.once('update', function (data) {
                 t.equal(data.announce, announceUrl)
-                t.equal(data.complete, 0)
+                t.equal(data.complete, 1)
                 t.equal(data.incomplete, 0)
+                client2.destroy()
 
-                client1.destroy()
-                server.close()
+                client1.stop()
+                client1.once('update', function (data) {
+                  t.equal(data.announce, announceUrl)
+                  t.equal(data.complete, 0)
+                  t.equal(data.incomplete, 0)
+
+                  client1.destroy()
+                  server.close()
+                })
               })
             })
           })