diff --git a/include/llvm/MC/MCInst.h b/include/llvm/MC/MCInst.h
index e34bc00ba98..4ed9dc7e3fe 100644
--- a/include/llvm/MC/MCInst.h
+++ b/include/llvm/MC/MCInst.h
@@ -18,6 +18,7 @@
 #define LLVM_MC_MCINST_H
 
 #include "llvm/ADT/SmallVector.h"
+#include "llvm/Support/DataTypes.h"
 
 namespace llvm {