diff --git a/include/openssl/e_os2.h b/include/openssl/e_os2.h
index 198ebdfc8858d078fdecad8a3651890e4d703b8b..99ea3477d7b42903c5c5a2c79446c49d258f36fb 100644
--- a/include/openssl/e_os2.h
+++ b/include/openssl/e_os2.h
@@ -245,7 +245,7 @@ typedef UINT64 uint64_t;
 #  define PRIu64 "%Lu"
 # elif (defined(__STDC_VERSION__) && __STDC_VERSION__ >= 199901L) || \
      defined(__osf__) || defined(__sgi) || defined(__hpux) || \
-     defined(OPENSSL_SYS_VMS)
+     defined(OPENSSL_SYS_VMS) || defined (__OpenBSD__)
 #  include <inttypes.h>
 # elif defined(_MSC_VER) && _MSC_VER<=1500
 /*