diff --git a/CryptoPkg/Library/Include/CrtLibSupport.h b/CryptoPkg/Library/Include/CrtLibSupport.h
index 62090c57cb..cd51e197e7 100644
--- a/CryptoPkg/Library/Include/CrtLibSupport.h
+++ b/CryptoPkg/Library/Include/CrtLibSupport.h
@@ -109,6 +109,7 @@ SPDX-License-Identifier: BSD-2-Clause-Patent
 typedef UINTN   size_t;
 typedef UINTN   off_t;
 typedef UINTN   u_int;
+typedef UINTN   intptr_t;
 typedef INTN    ptrdiff_t;
 typedef INTN    ssize_t;
 typedef INT64   time_t;