diff --git a/mlir/lib/Bindings/Python/PybindUtils.h b/mlir/lib/Bindings/Python/PybindUtils.h
--- a/mlir/lib/Bindings/Python/PybindUtils.h
+++ b/mlir/lib/Bindings/Python/PybindUtils.h
@@ -12,6 +12,7 @@
 #include "mlir-c/Support.h"
 #include "llvm/ADT/Optional.h"
 #include "llvm/ADT/Twine.h"
+#include "llvm/Support/DataTypes.h"
 
 #include <pybind11/pybind11.h>
 #include <pybind11/stl.h>