diff --git a/index.js b/index.js
index 08b82bc..2df9936 100644
--- a/index.js
+++ b/index.js
@@ -5,6 +5,7 @@ const safetyCatch = require('safety-catch')
 
 const MAX_BUFFERED = 32768
 const MAX_BACKLOG = Infinity // TODO: impl "open" backpressure
+const MAX_BATCH = 8 * 1024 * 1024
 
 class Channel {
   constructor (mux, info, userData, protocol, id, handshake, messages, onopen, onclose, ondestroy) {
@@ -337,6 +338,12 @@ module.exports = class Protomux {
   }
 
   _pushBatch (localId, buffer) {
+    if (this._batchState.end >= MAX_BATCH) {
+      this._sendBatch(this._batch, this._batchState)
+      this._batch = []
+      this._batchState = { buffer: null, start: 0, end: 1 }
+    }
+
     if (this._batch.length === 0 || this._batch[this._batch.length - 1].localId !== localId) {
       this._batchState.end++
       c.uint.preencode(this._batchState, localId)
diff --git a/package.json b/package.json
index 9e1cac4..e363092 100644
--- a/package.json
+++ b/package.json
@@ -10,7 +10,7 @@
     "safety-catch": "^1.0.1"
   },
   "devDependencies": {
-    "@hyperswarm/secret-stream": "^5.1.4",
+    "@hyperswarm/secret-stream": "^6.0.0",
     "brittle": "^2.0.1",
     "standard": "^16.0.4"
   },
diff --git a/test.js b/test.js
index af58cd0..6eefcdd 100644
--- a/test.js
+++ b/test.js
@@ -2,6 +2,7 @@ const Protomux = require('./')
 const SecretStream = require('@hyperswarm/secret-stream')
 const test = require('brittle')
 const c = require('compact-encoding')
+const b4a = require('b4a')
 
 test('basic', function (t) {
   const a = new Protomux(new SecretStream(true))
@@ -189,6 +190,52 @@ test('corks', function (t) {
   }
 })
 
+test('mega cork', function (t) {
+  const a = new Protomux(new SecretStream(true))
+
+  a.cork()
+
+  const ap = a.createChannel({
+    protocol: 'mega'
+  })
+
+  ap.open()
+
+  const a1 = ap.addMessage({ encoding: c.buffer })
+
+  const b = new Protomux(new SecretStream(false))
+
+  const bp = b.createChannel({
+    protocol: 'mega'
+  })
+
+  bp.open()
+
+  const b1 = bp.addMessage({ encoding: c.buffer })
+
+  replicate(a, b)
+
+  t.plan(32 + 4)
+
+  const buf = b4a.alloc(1024 * 1024)
+  const expected = []
+
+  for (let i = 0; i < 32; i++) {
+    a1.send(buf)
+    expected.push(buf)
+  }
+
+  a.uncork()
+
+  b.stream.on('data', function (data) {
+    t.ok(data.byteLength > 8000000, 'got big message')
+  })
+
+  b1.onmessage = function (message) {
+    t.alike(message, expected.shift())
+  }
+})
+
 test('handshake', function (t) {
   const a = new Protomux(new SecretStream(true))
   const b = new Protomux(new SecretStream(false))