diff -ruN a/src/cbang/openssl/BigNum.h b/src/cbang/openssl/BigNum.h
--- a/src/cbang/openssl/BigNum.h	2023-05-08 15:51:19.666666631 -0400
+++ b/src/cbang/openssl/BigNum.h	2023-05-08 15:52:07.769999960 -0400
@@ -32,6 +32,7 @@
 
 #pragma once
 
+#include <cstdint>
 #include <string>
 
 typedef struct bignum_st BIGNUM;