diff --git a/atom/browser/api/atom_api_web_contents.cc b/atom/browser/api/atom_api_web_contents.cc
index 081a88485540..38740abd0452 100644
--- a/atom/browser/api/atom_api_web_contents.cc
+++ b/atom/browser/api/atom_api_web_contents.cc
@@ -1033,13 +1033,17 @@ void WebContents::NavigationEntryCommitted(
        details.is_same_document, details.did_replace_entry);
 }
 
-int64_t WebContents::GetID() const {
-  int64_t process_id = web_contents()->GetRenderProcessHost()->GetID();
-  int64_t routing_id = web_contents()->GetRenderViewHost()->GetRoutingID();
+int64_t WebContents::GetIDForContents(content::WebContents* web_contents) {
+  int64_t process_id = web_contents->GetRenderProcessHost()->GetID();
+  int64_t routing_id = web_contents->GetMainFrame()->GetRoutingID();
   int64_t rv = (process_id << 32) + routing_id;
   return rv;
 }
 
+int64_t WebContents::GetID() const {
+  return WebContents::GetIDForContents(web_contents());
+}
+
 int WebContents::GetProcessID() const {
   return web_contents()->GetRenderProcessHost()->GetID();
 }
diff --git a/atom/browser/api/atom_api_web_contents.h b/atom/browser/api/atom_api_web_contents.h
index d94902894c57..5cd710149190 100644
--- a/atom/browser/api/atom_api_web_contents.h
+++ b/atom/browser/api/atom_api_web_contents.h
@@ -89,6 +89,8 @@ class WebContents : public mate::TrackableObject<WebContents>,
   static void BuildPrototype(v8::Isolate* isolate,
                              v8::Local<v8::FunctionTemplate> prototype);
 
+  static int64_t GetIDForContents(content::WebContents* web_contents);
+
   // Notifies to destroy any guest web contents before destroying self.
   void DestroyWebContents(bool async);
 
diff --git a/atom/browser/atom_browser_client.cc b/atom/browser/atom_browser_client.cc
index 8b7915bae9c9..b8a844a6886d 100644
--- a/atom/browser/atom_browser_client.cc
+++ b/atom/browser/atom_browser_client.cc
@@ -10,6 +10,7 @@
 
 #include "atom/browser/api/atom_api_app.h"
 #include "atom/browser/api/atom_api_protocol.h"
+#include "atom/browser/api/atom_api_web_contents.h"
 #include "atom/browser/atom_browser_context.h"
 #include "atom/browser/atom_browser_main_parts.h"
 #include "atom/browser/atom_quota_permission_context.h"
@@ -322,6 +323,11 @@ void AtomBrowserClient::AppendExtraCommandLineSwitches(
         web_contents, command_line);
     SessionPreferences::AppendExtraCommandLineSwitches(
         web_contents->GetBrowserContext(), command_line);
+
+    auto context_id = atom::api::WebContents::GetIDForContents(
+      web_contents);
+    command_line->AppendSwitchASCII(switches::kContextId,
+      base::IntToString(context_id));
   }
 }
 
diff --git a/atom/common/options_switches.cc b/atom/common/options_switches.cc
index eed6e7bc092f..c1cd185443c0 100644
--- a/atom/common/options_switches.cc
+++ b/atom/common/options_switches.cc
@@ -178,6 +178,9 @@ const char kAppUserModelId[] = "app-user-model-id";
 // The application path
 const char kAppPath[] = "app-path";
 
+// The context ID for this process
+const char kContextId[] = "context-id";
+
 // The command line switch versions of the options.
 const char kBackgroundColor[]  = "background-color";
 const char kPreloadScript[]    = "preload";
diff --git a/atom/common/options_switches.h b/atom/common/options_switches.h
index 525301971c8a..9d65bc376925 100644
--- a/atom/common/options_switches.h
+++ b/atom/common/options_switches.h
@@ -88,6 +88,7 @@ extern const char kRegisterServiceWorkerSchemes[];
 extern const char kSecureSchemes[];
 extern const char kAppUserModelId[];
 extern const char kAppPath[];
+extern const char kContextId[];
 
 extern const char kBackgroundColor[];
 extern const char kPreloadScript[];
diff --git a/lib/browser/rpc-server.js b/lib/browser/rpc-server.js
index 633360db1e27..20f62980c955 100644
--- a/lib/browser/rpc-server.js
+++ b/lib/browser/rpc-server.js
@@ -394,8 +394,8 @@ ipcMain.on('ELECTRON_BROWSER_DEREFERENCE', function (event, id) {
   objectsRegistry.remove(event.sender.getId(), id)
 })
 
-ipcMain.on('ELECTRON_BROWSER_CONTEXT_RELEASE', (e) => {
-  objectsRegistry.clear(e.sender.getId())
+ipcMain.on('ELECTRON_BROWSER_CONTEXT_RELEASE', (e, contextId) => {
+  objectsRegistry.clear(contextId)
   e.returnValue = null
 })
 
diff --git a/lib/renderer/api/remote.js b/lib/renderer/api/remote.js
index a4f8072ed576..3de99ecab255 100644
--- a/lib/renderer/api/remote.js
+++ b/lib/renderer/api/remote.js
@@ -268,7 +268,7 @@ ipcRenderer.on('ELECTRON_RENDERER_RELEASE_CALLBACK', (event, id) => {
 
 process.on('exit', () => {
   const command = 'ELECTRON_BROWSER_CONTEXT_RELEASE'
-  ipcRenderer.sendSync(command)
+  ipcRenderer.sendSync(command, initialContext)
 })
 
 exports.require = (module) => {
@@ -295,6 +295,15 @@ exports.getCurrentWebContents = () => {
   return metaToValue(ipcRenderer.sendSync('ELECTRON_BROWSER_CURRENT_WEB_CONTENTS'))
 }
 
+const CONTEXT_ARG = '--context-id='
+let initialContext = process.argv.find(arg => arg.startsWith(CONTEXT_ARG))
+if (initialContext) {
+  initialContext = parseInt(initialContext.substr(CONTEXT_ARG.length), 10)
+} else {
+  // In sandbox we need to pull this from remote
+  initialContext = exports.getCurrentWebContents().getId()
+}
+
 // Get a global object in browser.
 exports.getGlobal = (name) => {
   const command = 'ELECTRON_BROWSER_GLOBAL'