diff --git a/src/libsodium/crypto_auth/hmacsha256/ref/hmac_hmacsha256.c b/src/libsodium/crypto_auth/hmacsha256/ref/hmac_hmacsha256.c
index 4aec36f4..2e7564a6 100644
--- a/src/libsodium/crypto_auth/hmacsha256/ref/hmac_hmacsha256.c
+++ b/src/libsodium/crypto_auth/hmacsha256/ref/hmac_hmacsha256.c
@@ -26,7 +26,7 @@ int crypto_auth(unsigned char *out,const unsigned char *in,unsigned long long in
 {
   unsigned char h[32];
   unsigned char padded[128];
-  int i;
+  unsigned long long i;
   unsigned long long bits = 512 + (inlen << 3);
 
   for (i = 0;i < 32;++i) h[i] = iv[i];
diff --git a/src/libsodium/crypto_auth/hmacsha512256/ref/hmac_hmacsha512256.c b/src/libsodium/crypto_auth/hmacsha512256/ref/hmac_hmacsha512256.c
index 7636e869..be871ced 100644
--- a/src/libsodium/crypto_auth/hmacsha512256/ref/hmac_hmacsha512256.c
+++ b/src/libsodium/crypto_auth/hmacsha512256/ref/hmac_hmacsha512256.c
@@ -26,7 +26,7 @@ int crypto_auth(unsigned char *out,const unsigned char *in,unsigned long long in
 {
   unsigned char h[64];
   unsigned char padded[256];
-  int i;
+  unsigned long long i;
   unsigned long long bytes = 128 + inlen;
 
   for (i = 0;i < 64;++i) h[i] = iv[i];
diff --git a/src/libsodium/crypto_hash/sha256/ref/hash_sha256.c b/src/libsodium/crypto_hash/sha256/ref/hash_sha256.c
index 2bd5578d..774271d6 100644
--- a/src/libsodium/crypto_hash/sha256/ref/hash_sha256.c
+++ b/src/libsodium/crypto_hash/sha256/ref/hash_sha256.c
@@ -26,7 +26,7 @@ int crypto_hash(unsigned char *out,const unsigned char *in,unsigned long long in
 {
   unsigned char h[32];
   unsigned char padded[128];
-  int i;
+  unsigned long long i;
   unsigned long long bits = inlen << 3;
 
   for (i = 0;i < 32;++i) h[i] = iv[i];
diff --git a/src/libsodium/crypto_hash/sha512/ref/hash_sha512.c b/src/libsodium/crypto_hash/sha512/ref/hash_sha512.c
index 66b9ddc6..7cc8b85d 100644
--- a/src/libsodium/crypto_hash/sha512/ref/hash_sha512.c
+++ b/src/libsodium/crypto_hash/sha512/ref/hash_sha512.c
@@ -26,7 +26,7 @@ int crypto_hash(unsigned char *out,const unsigned char *in,unsigned long long in
 {
   unsigned char h[64];
   unsigned char padded[256];
-  int i;
+  unsigned long long i;
   unsigned long long bytes = inlen;
 
   for (i = 0;i < 64;++i) h[i] = iv[i];