diff --git a/netwerk/protocol/ftp/FTPChannelParent.cpp b/netwerk/protocol/ftp/FTPChannelParent.cpp
index 365bdc9130bb..99d4886bf973 100644
--- a/netwerk/protocol/ftp/FTPChannelParent.cpp
+++ b/netwerk/protocol/ftp/FTPChannelParent.cpp
@@ -55,6 +55,8 @@ FTPChannelParent::FTPChannelParent(const PBrowserOrId& aIframeEmbedding,
   }
 
   mObserver = new OfflineObserver(this);
+
+  mEventQ = new ChannelEventQueue(static_cast<nsIParentChannel*>(this));
 }
 
 FTPChannelParent::~FTPChannelParent()
@@ -243,6 +245,32 @@ FTPChannelParent::RecvResume()
   return true;
 }
 
+class FTPDivertDataAvailableEvent : public ChannelEvent
+{
+public:
+  FTPDivertDataAvailableEvent(FTPChannelParent* aParent,
+                              const nsCString& data,
+                              const uint64_t& offset,
+                              const uint32_t& count)
+  : mParent(aParent)
+  , mData(data)
+  , mOffset(offset)
+  , mCount(count)
+  {
+  }
+
+  void Run()
+  {
+    mParent->DivertOnDataAvailable(mData, mOffset, mCount);
+  }
+
+private:
+  FTPChannelParent* mParent;
+  nsCString mData;
+  uint64_t mOffset;
+  uint32_t mCount;
+};
+
 bool
 FTPChannelParent::RecvDivertOnDataAvailable(const nsCString& data,
                                             const uint64_t& offset,
@@ -260,6 +288,35 @@ FTPChannelParent::RecvDivertOnDataAvailable(const nsCString& data,
     return true;
   }
 
+  if (mEventQ->ShouldEnqueue()) {
+    mEventQ->Enqueue(new FTPDivertDataAvailableEvent(this, data, offset,
+                                                     count));
+    return true;
+  }
+
+  DivertOnDataAvailable(data, offset, count);
+  return true;
+}
+
+void
+FTPChannelParent::DivertOnDataAvailable(const nsCString& data,
+                                        const uint64_t& offset,
+                                        const uint32_t& count)
+{
+  LOG(("FTPChannelParent::DivertOnDataAvailable [this=%p]\n", this));
+
+  if (NS_WARN_IF(!mDivertingFromChild)) {
+    MOZ_ASSERT(mDivertingFromChild,
+               "Cannot DivertOnDataAvailable if diverting is not set!");
+    FailDiversion(NS_ERROR_UNEXPECTED);
+    return;
+  }
+
+  // Drop OnDataAvailables if the parent was canceled already.
+  if (NS_FAILED(mStatus)) {
+    return;
+  }
+
   nsCOMPtr<nsIInputStream> stringStream;
   nsresult rv = NS_NewByteInputStream(getter_AddRefs(stringStream), data.get(),
                                       count, NS_ASSIGNMENT_DEPEND);
@@ -268,9 +325,11 @@ FTPChannelParent::RecvDivertOnDataAvailable(const nsCString& data,
       mChannel->Cancel(rv);
     }
     mStatus = rv;
-    return true;
+    return;
   }
 
+  AutoEventEnqueuer ensureSerialDispatch(mEventQ);
+
   rv = OnDataAvailable(mChannel, nullptr, stringStream, offset, count);
 
   stringStream->Close();
@@ -280,9 +339,27 @@ FTPChannelParent::RecvDivertOnDataAvailable(const nsCString& data,
     }
     mStatus = rv;
   }
-  return true;
 }
 
+class FTPDivertStopRequestEvent : public ChannelEvent
+{
+public:
+  FTPDivertStopRequestEvent(FTPChannelParent* aParent,
+                            const nsresult& statusCode)
+  : mParent(aParent)
+  , mStatusCode(statusCode)
+  {
+  }
+
+  void Run() {
+    mParent->DivertOnStopRequest(mStatusCode);
+  }
+
+private:
+  FTPChannelParent* mParent;
+  nsresult mStatusCode;
+};
+
 bool
 FTPChannelParent::RecvDivertOnStopRequest(const nsresult& statusCode)
 {
@@ -293,6 +370,27 @@ FTPChannelParent::RecvDivertOnStopRequest(const nsresult& statusCode)
     return false;
   }
 
+  if (mEventQ->ShouldEnqueue()) {
+    mEventQ->Enqueue(new FTPDivertStopRequestEvent(this, statusCode));
+    return true;
+  }
+
+  DivertOnStopRequest(statusCode);
+  return true;
+}
+
+void
+FTPChannelParent::DivertOnStopRequest(const nsresult& statusCode)
+{
+  LOG(("FTPChannelParent::DivertOnStopRequest [this=%p]\n", this));
+
+  if (NS_WARN_IF(!mDivertingFromChild)) {
+    MOZ_ASSERT(mDivertingFromChild,
+               "Cannot DivertOnStopRequest if diverting is not set!");
+    FailDiversion(NS_ERROR_UNEXPECTED);
+    return;
+  }
+
   // Honor the channel's status even if the underlying transaction completed.
   nsresult status = NS_FAILED(mStatus) ? mStatus : statusCode;
 
@@ -304,10 +402,26 @@ FTPChannelParent::RecvDivertOnStopRequest(const nsresult& statusCode)
     }
   }
 
+  AutoEventEnqueuer ensureSerialDispatch(mEventQ);
   OnStopRequest(mChannel, nullptr, status);
-  return true;
 }
 
+class FTPDivertCompleteEvent : public ChannelEvent
+{
+public:
+  explicit FTPDivertCompleteEvent(FTPChannelParent* aParent)
+  : mParent(aParent)
+  {
+  }
+
+  void Run() {
+    mParent->DivertComplete();
+  }
+
+private:
+  FTPChannelParent* mParent;
+};
+
 bool
 FTPChannelParent::RecvDivertComplete()
 {
@@ -318,13 +432,31 @@ FTPChannelParent::RecvDivertComplete()
     return false;
   }
 
+  if (mEventQ->ShouldEnqueue()) {
+    mEventQ->Enqueue(new FTPDivertCompleteEvent(this));
+    return true;
+  }
+
+  DivertComplete();
+  return true;
+}
+
+void
+FTPChannelParent::DivertComplete()
+{
+  LOG(("FTPChannelParent::DivertComplete [this=%p]\n", this));
+
+  if (NS_WARN_IF(!mDivertingFromChild)) {
+    MOZ_ASSERT(mDivertingFromChild,
+               "Cannot DivertComplete if diverting is not set!");
+    FailDiversion(NS_ERROR_UNEXPECTED);
+    return;
+  }
+
   nsresult rv = ResumeForDiversion();
   if (NS_WARN_IF(NS_FAILED(rv))) {
     FailDiversion(NS_ERROR_UNEXPECTED);
-    return false;
   }
-
-  return true;
 }
 
 //-----------------------------------------------------------------------------
@@ -588,14 +720,17 @@ FTPChannelParent::StartDiversion()
     }
   }
 
-  // Call OnStartRequest for the "DivertTo" listener.
-  nsresult rv = OnStartRequest(mChannel, nullptr);
-  if (NS_FAILED(rv)) {
-    if (mChannel) {
-      mChannel->Cancel(rv);
+  {
+    AutoEventEnqueuer ensureSerialDispatch(mEventQ);
+    // Call OnStartRequest for the "DivertTo" listener.
+    nsresult rv = OnStartRequest(mChannel, nullptr);
+    if (NS_FAILED(rv)) {
+      if (mChannel) {
+        mChannel->Cancel(rv);
+      }
+      mStatus = rv;
+      return;
     }
-    mStatus = rv;
-    return;
   }
 
   // After OnStartRequest has been called, tell FTPChannelChild to divert the
diff --git a/netwerk/protocol/ftp/FTPChannelParent.h b/netwerk/protocol/ftp/FTPChannelParent.h
index fcb2511acfb4..b4378f98719b 100644
--- a/netwerk/protocol/ftp/FTPChannelParent.h
+++ b/netwerk/protocol/ftp/FTPChannelParent.h
@@ -79,6 +79,16 @@ protected:
   // ChildChannel.  Used during HTTP->FTP redirects.
   bool ConnectChannel(const uint32_t& channelId);
 
+  void DivertOnDataAvailable(const nsCString& data,
+                             const uint64_t& offset,
+                             const uint32_t& count);
+  void DivertOnStopRequest(const nsresult& statusCode);
+  void DivertComplete();
+
+  friend class FTPDivertDataAvailableEvent;
+  friend class FTPDivertStopRequestEvent;
+  friend class FTPDivertCompleteEvent;
+
   virtual bool RecvCancel(const nsresult& status) override;
   virtual bool RecvSuspend() override;
   virtual bool RecvResume() override;
@@ -119,6 +129,8 @@ protected:
   bool mSuspendedForDiversion;
   nsRefPtr<OfflineObserver> mObserver;
   nsRefPtr<mozilla::dom::TabParent> mTabParent;
+
+  nsRefPtr<ChannelEventQueue> mEventQ;
 };
 
 } // namespace net