diff --git a/src/python/pybind11/core.hh b/src/python/pybind11/core.hh
index 4fc9cc0a66..33562e8fd4 100644
--- a/src/python/pybind11/core.hh
+++ b/src/python/pybind11/core.hh
@@ -38,6 +38,7 @@
 #ifndef __PYTHON_PYBIND11_CORE_HH__
 #define __PYTHON_PYBIND11_CORE_HH__
 
+#include "pybind11/cast.h"
 #include "pybind11/stl_bind.h"
 
 #include <vector>