diff --git a/include/openssl/digest.h b/include/openssl/digest.h
index 87de3df..2de84f7 100644
--- a/include/openssl/digest.h
+++ b/include/openssl/digest.h
@@ -283,5 +283,7 @@
 #endif
 
 #define DIGEST_R_INPUT_NOT_INITIALIZED 100
+#define DIGEST_R_DECODE_ERROR 101
+#define DIGEST_R_UNKNOWN_HASH 102
 
 #endif  /* OPENSSL_HEADER_DIGEST_H */