diff --git a/engine/src/flutter/tools/debugger/debugger.cc b/engine/src/flutter/tools/debugger/debugger.cc
index a764ae59571..4fdbbe88474 100644
--- a/engine/src/flutter/tools/debugger/debugger.cc
+++ b/engine/src/flutter/tools/debugger/debugger.cc
@@ -66,13 +66,11 @@ void SkyDebugger::OnEmbed(
 }
 
 void SkyDebugger::OnViewManagerDisconnected(mojo::ViewManager* view_manager) {
-  CHECK(false); // FIXME: This is dead code, why?
   view_manager_ = nullptr;
   root_ = nullptr;
 }
 
 void SkyDebugger::OnViewDestroyed(mojo::View* view) {
-  CHECK(false); // FIXME: This is dead code, why?
   view->RemoveObserver(this);
 }
 
@@ -101,6 +99,16 @@ void SkyDebugger::NavigateToURL(const mojo::String& url) {
   }
 }
 
+void SkyDebugger::Shutdown() {
+  // Make sure we shut down mojo before quitting the message loop or things
+  // like blink::shutdown() may try to talk to the message loop and crash.
+  window_manager_app_.reset();
+
+  // TODO(eseidel): This still hits an X11 error which I don't understand
+  // "X Error of failed request:  GLXBadDrawable", crbug.com/430581
+  mojo::ApplicationImpl::Terminate();
+}
+
 void SkyDebugger::InjectInspector() {
   InspectorServicePtr inspector_service;
   mojo::ConnectToService(viewer_services_.get(), &inspector_service);
diff --git a/engine/src/flutter/tools/debugger/debugger.h b/engine/src/flutter/tools/debugger/debugger.h
index 4bd60db0681..e48a6280d7b 100644
--- a/engine/src/flutter/tools/debugger/debugger.h
+++ b/engine/src/flutter/tools/debugger/debugger.h
@@ -36,6 +36,7 @@ class SkyDebugger : public mojo::ApplicationDelegate,
   // Overridden from Debugger
   void NavigateToURL(const mojo::String& url) override;
   void InjectInspector() override;
+  void Shutdown() override;
 
  private:
   // Overridden from mojo::ApplicationDelegate:
diff --git a/engine/src/flutter/tools/debugger/debugger.mojom b/engine/src/flutter/tools/debugger/debugger.mojom
index 75e2f2f8a8a..8e5f23bc4e4 100644
--- a/engine/src/flutter/tools/debugger/debugger.mojom
+++ b/engine/src/flutter/tools/debugger/debugger.mojom
@@ -7,4 +7,5 @@ module sky;
 interface Debugger {
   NavigateToURL(string url);
   InjectInspector();
+  Shutdown();
 };
diff --git a/engine/src/flutter/tools/debugger/prompt/prompt.cc b/engine/src/flutter/tools/debugger/prompt/prompt.cc
index b8007a78276..8a5ad048f5f 100644
--- a/engine/src/flutter/tools/debugger/prompt/prompt.cc
+++ b/engine/src/flutter/tools/debugger/prompt/prompt.cc
@@ -132,7 +132,7 @@ class Prompt : public mojo::ApplicationDelegate {
 
   void Quit() {
     std::cout << "quitting" << std::endl;
-    exit(0);
+    debugger_->Shutdown();
   }
 
   void ToggleTracing() {