diff --git a/panda/src/dxgsg9/dxShaderContext9.cxx b/panda/src/dxgsg9/dxShaderContext9.cxx
index 4585281b4a..663ada13a8 100644
--- a/panda/src/dxgsg9/dxShaderContext9.cxx
+++ b/panda/src/dxgsg9/dxShaderContext9.cxx
@@ -16,6 +16,7 @@
 //
 ////////////////////////////////////////////////////////////////////
 
+#include "dxGraphicsStateGuardian9.h"
 #include "dxShaderContext9.h"
 
 TypeHandle CLP(ShaderContext)::_type_handle;