diff --git a/clang/include/clang/Sema/RISCVIntrinsicManager.h b/clang/include/clang/Sema/RISCVIntrinsicManager.h
index 66e7dbd281c1d..731bc3ae1c9d2 100644
--- a/clang/include/clang/Sema/RISCVIntrinsicManager.h
+++ b/clang/include/clang/Sema/RISCVIntrinsicManager.h
@@ -14,6 +14,8 @@
 #ifndef LLVM_CLANG_SEMA_RISCVINTRINSICMANAGER_H
 #define LLVM_CLANG_SEMA_RISCVINTRINSICMANAGER_H
 
+#include <cstdint>
+
 namespace clang {
 class LookupResult;
 class IdentifierInfo;