diff --git a/shell/common/platform_view.h b/shell/common/platform_view.h
index 346c0b9bbde5a..4b5bf66d5205b 100644
--- a/shell/common/platform_view.h
+++ b/shell/common/platform_view.h
@@ -37,6 +37,8 @@ class PlatformView : public std::enable_shared_from_this<PlatformView> {
 
   virtual ~PlatformView();
 
+  virtual void Attach() = 0;
+
   void DispatchPlatformMessage(ftl::RefPtr<blink::PlatformMessage> message);
   void DispatchSemanticsAction(int32_t id, blink::SemanticsAction action);
   void SetSemanticsEnabled(bool enabled);
diff --git a/shell/platform/android/platform_view_android.h b/shell/platform/android/platform_view_android.h
index 2ac7ad0143df3..ab522b475b3b2 100644
--- a/shell/platform/android/platform_view_android.h
+++ b/shell/platform/android/platform_view_android.h
@@ -28,7 +28,7 @@ class PlatformViewAndroid : public PlatformView {
 
   ~PlatformViewAndroid() override;
 
-  void Attach();
+  virtual void Attach() override;
 
   void Detach();
 
diff --git a/shell/platform/darwin/desktop/platform_view_mac.h b/shell/platform/darwin/desktop/platform_view_mac.h
index 625d3e2a53e55..ae778a6602c2c 100644
--- a/shell/platform/darwin/desktop/platform_view_mac.h
+++ b/shell/platform/darwin/desktop/platform_view_mac.h
@@ -21,7 +21,7 @@ class PlatformViewMac : public PlatformView, public GPUSurfaceGLDelegate {
 
   ~PlatformViewMac() override;
 
-  void Attach();
+  virtual void Attach() override;
 
   void SetupAndLoadDart();
 
diff --git a/shell/platform/darwin/ios/platform_view_ios.h b/shell/platform/darwin/ios/platform_view_ios.h
index 034020ebe702b..b8e36dc624f94 100644
--- a/shell/platform/darwin/ios/platform_view_ios.h
+++ b/shell/platform/darwin/ios/platform_view_ios.h
@@ -25,7 +25,7 @@ class PlatformViewIOS : public PlatformView {
 
   ~PlatformViewIOS() override;
 
-  void Attach();
+  virtual void Attach() override;
 
   void NotifyCreated();
 
diff --git a/shell/testing/platform_view_test.h b/shell/testing/platform_view_test.h
index 0f15ba359a048..a63df9b3b9ae2 100644
--- a/shell/testing/platform_view_test.h
+++ b/shell/testing/platform_view_test.h
@@ -19,7 +19,7 @@ class PlatformViewTest : public PlatformView {
 
   ~PlatformViewTest();
 
-  void Attach();
+  virtual void Attach() override;
 
   bool ResourceContextMakeCurrent() override;