diff --git a/sha3.h b/sha3.h
index 4974a9bbc..84dca241b 100644
--- a/sha3.h
+++ b/sha3.h
@@ -21,7 +21,7 @@ static inline void SHA3_256(struct ethash_blockhash const* ret, uint8_t const *d
     sha3_256((uint8_t*)ret, 32, data, size);
 }
 
-static inline void SHA3_512(uint8_t const *ret, uint8_t const *data, const size_t size)
+static inline void SHA3_512(uint8_t *ret, uint8_t const *data, const size_t size)
 {
     sha3_512(ret, 64, data, size);
 }