diff --git a/libcef/browser/browser_host_impl.cc b/libcef/browser/browser_host_impl.cc
index eca55e5a0..933a2bdf8 100644
--- a/libcef/browser/browser_host_impl.cc
+++ b/libcef/browser/browser_host_impl.cc
@@ -850,9 +850,7 @@ void CefBrowserHostImpl::CloseDevTools() {
   if (CEF_CURRENTLY_ON_UIT()) {
     if (!devtools_frontend_)
       return;
-    devtools_observer_.reset();
     devtools_frontend_->Close();
-    devtools_frontend_ = NULL;
   } else {
     CEF_POST_TASK(CEF_UIT,
         base::Bind(&CefBrowserHostImpl::CloseDevTools, this));
diff --git a/libcef/browser/devtools_frontend.cc b/libcef/browser/devtools_frontend.cc
index 6ce309ab3..5d1b75cb1 100644
--- a/libcef/browser/devtools_frontend.cc
+++ b/libcef/browser/devtools_frontend.cc
@@ -7,6 +7,7 @@
 #include "libcef/browser/content_browser_client.h"
 #include "libcef/browser/devtools_delegate.h"
 #include "libcef/browser/request_context_impl.h"
+#include "libcef/browser/thread_util.h"
 
 #include "base/command_line.h"
 #include "base/json/json_reader.h"
@@ -73,7 +74,8 @@ void CefDevToolsFrontend::Focus() {
 }
 
 void CefDevToolsFrontend::Close() {
-  frontend_browser_->CloseBrowser(true);
+  CEF_POST_TASK(CEF_UIT,
+      base::Bind(&CefBrowserHostImpl::CloseBrowser, frontend_browser_, true));
 }
 
 CefDevToolsFrontend::CefDevToolsFrontend(
@@ -155,5 +157,6 @@ void CefDevToolsFrontend::DispatchProtocolMessage(
 void CefDevToolsFrontend::AgentHostClosed(
     content::DevToolsAgentHost* agent_host,
     bool replaced) {
+  DCHECK(agent_host == agent_host_.get());
   Close();
 }