--- ./include/sha2_openbsd.h.orig
+++ ./include/sha2_openbsd.h
@@ -63,7 +63,10 @@
 	u_int8_t	buffer[SHA512_BLOCK_LENGTH];
 } SHA2_CTX;
 
-__BEGIN_DECLS
+#ifdef  __cplusplus
+extern "C" {
+#endif
+
 void SHA224Init(SHA2_CTX *);
 void SHA224Transform(u_int32_t state[8], const u_int8_t [SHA224_BLOCK_LENGTH]);
 void SHA224Update(SHA2_CTX *, const u_int8_t *, size_t)
@@ -131,6 +134,8 @@
 char *SHA512Data(const u_int8_t *, size_t, char *)
 	__attribute__((__bounded__(__string__,1,2)))
 	__attribute__((__bounded__(__minbytes__,3,SHA512_DIGEST_STRING_LENGTH)));
-__END_DECLS
+#ifdef  __cplusplus
+}
+#endif
 
 #endif /* _SHA2_H */
--- ./include/md5_openbsd.h.orig
+++ ./include/md5_openbsd.h
@@ -15,6 +15,8 @@
 #ifndef _MD5_H_
 #define _MD5_H_
 
+#include <sys/types.h>
+
 #define	MD5_BLOCK_LENGTH		64
 #define	MD5_DIGEST_LENGTH		16
 #define	MD5_DIGEST_STRING_LENGTH	(MD5_DIGEST_LENGTH * 2 + 1)
@@ -25,7 +27,9 @@
 	u_int8_t buffer[MD5_BLOCK_LENGTH];	/* input buffer */
 } MD5_CTX;
 
-__BEGIN_DECLS
+#ifdef  __cplusplus
+extern "C" {
+#endif
 void	 MD5Init(MD5_CTX *);
 void	 MD5Update(MD5_CTX *, const u_int8_t *, size_t)
 		__attribute__((__bounded__(__string__,2,3)));
@@ -44,6 +48,8 @@
 char	*MD5Data(const u_int8_t *, size_t, char *)
 		__attribute__((__bounded__(__string__,1,2)))
 		__attribute__((__bounded__(__minbytes__,3,MD5_DIGEST_STRING_LENGTH)));
-__END_DECLS
+#ifdef  __cplusplus
+}
+#endif
 
 #endif /* _MD5_H_ */