diff --git a/atom/browser/api/atom_api_session.cc b/atom/browser/api/atom_api_session.cc
index 2b352e52f7c5..222591e92e92 100644
--- a/atom/browser/api/atom_api_session.cc
+++ b/atom/browser/api/atom_api_session.cc
@@ -386,12 +386,16 @@ void Session::EnableNetworkEmulation(const mate::Dictionary& options) {
 
   browser_context_->network_controller_handle()->SetNetworkState(
       devtools_network_emulation_client_id_, std::move(conditions));
+  browser_context_->network_delegate()->SetDevToolsNetworkEmulationClientId(
+      devtools_network_emulation_client_id_);
 }
 
 void Session::DisableNetworkEmulation() {
   scoped_ptr<brightray::DevToolsNetworkConditions> conditions;
   browser_context_->network_controller_handle()->SetNetworkState(
       devtools_network_emulation_client_id_, std::move(conditions));
+  browser_context_->network_delegate()->SetDevToolsNetworkEmulationClientId(
+      std::string());
 }
 
 void Session::SetCertVerifyProc(v8::Local<v8::Value> val,
diff --git a/atom/browser/net/atom_network_delegate.cc b/atom/browser/net/atom_network_delegate.cc
index 86bfe12079ad..3143cd3b2575 100644
--- a/atom/browser/net/atom_network_delegate.cc
+++ b/atom/browser/net/atom_network_delegate.cc
@@ -4,15 +4,16 @@
 
 #include "atom/browser/net/atom_network_delegate.h"
 
-#include <string>
 #include <utility>
 
 #include "atom/common/native_mate_converters/net_converter.h"
 #include "base/stl_util.h"
 #include "base/strings/string_util.h"
+#include "brightray/browser/net/devtools_network_transaction.h"
 #include "content/public/browser/browser_thread.h"
 #include "net/url_request/url_request.h"
 
+using brightray::DevToolsNetworkTransaction;
 using content::BrowserThread;
 
 namespace atom {
@@ -226,6 +227,12 @@ void AtomNetworkDelegate::SetResponseListenerInIO(
     response_listeners_[type] = { patterns, callback };
 }
 
+void AtomNetworkDelegate::SetDevToolsNetworkEmulationClientId(
+    const std::string& client_id) {
+  base::AutoLock auto_lock(lock_);
+  client_id_ = client_id;
+}
+
 int AtomNetworkDelegate::OnBeforeURLRequest(
     net::URLRequest* request,
     const net::CompletionCallback& callback,
@@ -241,6 +248,16 @@ int AtomNetworkDelegate::OnBeforeSendHeaders(
     net::URLRequest* request,
     const net::CompletionCallback& callback,
     net::HttpRequestHeaders* headers) {
+  std::string client_id;
+  {
+    base::AutoLock auto_lock(lock_);
+    client_id = client_id_;
+  }
+
+  if (!client_id.empty())
+    headers->SetHeader(
+        DevToolsNetworkTransaction::kDevToolsEmulateNetworkConditionsClientId,
+        client_id);
   if (!ContainsKey(response_listeners_, kOnBeforeSendHeaders))
     return brightray::NetworkDelegate::OnBeforeSendHeaders(
         request, callback, headers);
diff --git a/atom/browser/net/atom_network_delegate.h b/atom/browser/net/atom_network_delegate.h
index ee159df60f13..92ea6415e69e 100644
--- a/atom/browser/net/atom_network_delegate.h
+++ b/atom/browser/net/atom_network_delegate.h
@@ -7,9 +7,11 @@
 
 #include <map>
 #include <set>
+#include <string>
 
 #include "brightray/browser/network_delegate.h"
 #include "base/callback.h"
+#include "base/synchronization/lock.h"
 #include "base/values.h"
 #include "extensions/common/url_pattern.h"
 #include "net/base/net_errors.h"
@@ -68,6 +70,8 @@ class AtomNetworkDelegate : public brightray::NetworkDelegate {
                                const URLPatterns& patterns,
                                const ResponseListener& callback);
 
+  void SetDevToolsNetworkEmulationClientId(const std::string& client_id);
+
  protected:
   // net::NetworkDelegate:
   int OnBeforeURLRequest(net::URLRequest* request,
@@ -116,6 +120,10 @@ class AtomNetworkDelegate : public brightray::NetworkDelegate {
   std::map<ResponseEvent, ResponseListenerInfo> response_listeners_;
   std::map<uint64_t, net::CompletionCallback> callbacks_;
 
+  base::Lock lock_;
+  // Client id for devtools network emulation.
+  std::string client_id_;
+
   DISALLOW_COPY_AND_ASSIGN(AtomNetworkDelegate);
 };