diff --git a/shell/browser/api/electron_api_web_contents.cc b/shell/browser/api/electron_api_web_contents.cc
index fb2f037b7808..41ed4592a2f7 100644
--- a/shell/browser/api/electron_api_web_contents.cc
+++ b/shell/browser/api/electron_api_web_contents.cc
@@ -2147,8 +2147,11 @@ void WebContents::DevToolsOpened() {
   // Inherit owner window in devtools when it doesn't have one.
   auto* devtools = inspectable_web_contents_->GetDevToolsWebContents();
   bool has_window = devtools->GetUserData(NativeWindowRelay::UserDataKey());
-  if (owner_window() && !has_window)
+  if (owner_window_ && !has_window) {
+    DCHECK(!owner_window_.WasInvalidated());
+    DCHECK_EQ(handle->owner_window(), nullptr);
     handle->SetOwnerWindow(devtools, owner_window());
+  }
 
   Emit("devtools-opened");
 }
diff --git a/shell/browser/ui/inspectable_web_contents.cc b/shell/browser/ui/inspectable_web_contents.cc
index 60d481a9d5ca..e80d6a6d7662 100644
--- a/shell/browser/ui/inspectable_web_contents.cc
+++ b/shell/browser/ui/inspectable_web_contents.cc
@@ -530,6 +530,8 @@ void InspectableWebContents::CloseWindow() {
 }
 
 void InspectableWebContents::LoadCompleted() {
+  DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
+
   frontend_loaded_ = true;
   if (managed_devtools_web_contents_)
     view_->ShowDevTools(activate_);
diff --git a/shell/browser/ui/inspectable_web_contents.h b/shell/browser/ui/inspectable_web_contents.h
index 012f613895e3..87fe41aaad7f 100644
--- a/shell/browser/ui/inspectable_web_contents.h
+++ b/shell/browser/ui/inspectable_web_contents.h
@@ -15,6 +15,7 @@
 #include "base/containers/unique_ptr_adapters.h"
 #include "base/memory/raw_ptr.h"
 #include "base/memory/weak_ptr.h"
+#include "base/sequence_checker.h"
 #include "chrome/browser/devtools/devtools_embedder_message_dispatcher.h"
 #include "content/public/browser/devtools_agent_host.h"
 #include "content/public/browser/devtools_frontend_host.h"
@@ -271,6 +272,8 @@ class InspectableWebContents
   // use, which guarantees that this set must not be persisted.
   base::flat_set<std::string> synced_setting_names_;
 
+  SEQUENCE_CHECKER(sequence_checker_);
+
   base::WeakPtrFactory<InspectableWebContents> weak_factory_{this};
 };