diff --git a/viewer/compositor/surface_holder.h b/viewer/compositor/surface_holder.h
index bf017c21c7aed029aa9f2952abc3154133c1c904..cd34c90e8aa8a7c1f29bb44ba4d8dc0c0c6c2669 100644
--- a/viewer/compositor/surface_holder.h
+++ b/viewer/compositor/surface_holder.h
@@ -8,6 +8,7 @@
 #include "base/callback_forward.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/weak_ptr.h"
+#include "mojo/public/cpp/bindings/binding.h"
 #include "mojo/services/surfaces/public/interfaces/surface_id.mojom.h"
 #include "mojo/services/surfaces/public/interfaces/surfaces.mojom.h"
 #include "ui/gfx/geometry/rect.h"
diff --git a/viewer/internals.h b/viewer/internals.h
index 45354522fae9fd9a2e44948504d376080411337e..dc1a61de2f603af7f3ddda95886fa7058b75e5e1 100644
--- a/viewer/internals.h
+++ b/viewer/internals.h
@@ -8,6 +8,7 @@
 #include "base/memory/weak_ptr.h"
 #include "base/supports_user_data.h"
 #include "dart/runtime/include/dart_api.h"
+#include "mojo/public/cpp/bindings/binding.h"
 #include "mojo/public/interfaces/application/shell.mojom.h"
 #include "sky/services/testing/test_harness.mojom.h"