diff --git a/sky/shell/gpu/rasterizer.cc b/sky/shell/gpu/rasterizer.cc
index 4e84111..dc4530c 100644
--- a/sky/shell/gpu/rasterizer.cc
+++ b/sky/shell/gpu/rasterizer.cc
@@ -53,6 +53,9 @@
   if (size.IsEmpty())
     return;
 
+  if (surface_->GetSize() != size)
+    surface_->Resize(size);
+
   EnsureGLContext();
   CHECK(context_->MakeCurrent(surface_.get()));
   EnsureGaneshSurface(surface_->GetBackingFrameBufferObject(), size);