diff --git a/engines/myst3/gfx_opengl_shaders.cpp b/engines/myst3/gfx_opengl_shaders.cpp
index 2112520ac03..086df3ff6b8 100644
--- a/engines/myst3/gfx_opengl_shaders.cpp
+++ b/engines/myst3/gfx_opengl_shaders.cpp
@@ -166,6 +166,7 @@ void ShaderRenderer::clear() {
 
 void ShaderRenderer::setupCameraOrtho2D() {
   glViewport(0, 0, kOriginalWidth, kOriginalHeight);
+  _viewport = Math::Rect2d(Math::Vector2d(0, 0), Math::Vector2d(kOriginalWidth, kOriginalHeight));
 }
 
 void ShaderRenderer::setupCameraPerspective(float pitch, float heading, float fov) {