diff --git a/libraries/Hash/src/Hash.h b/libraries/Hash/src/Hash.h
index d774fd6b1..774b8aad1 100644
--- a/libraries/Hash/src/Hash.h
+++ b/libraries/Hash/src/Hash.h
@@ -35,7 +35,7 @@ void sha1(String data, uint8_t hash[20]);
 
 String sha1(uint8_t* data, uint32_t size);
 String sha1(char* data, uint32_t size);
-String sha1(uint8_t* data, uint32_t size);
+String sha1(const uint8_t* data, uint32_t size);
 String sha1(const char* data, uint32_t size);
 String sha1(String data);