diff --git a/hash/md2.cpp b/hash/md2.cpp
index 53434727..84c5d1b2 100644
--- a/hash/md2.cpp
+++ b/hash/md2.cpp
@@ -81,14 +81,6 @@ MD2::update (const uint8_t *restrict first, const uint8_t *restrict last) noexce
 }
 
 
-//-----------------------------------------------------------------------------
-void
-MD2::update (const void *restrict data, size_t size) noexcept
-{
-    update (static_cast<const uint8_t*> (data), size);
-}
-
-
 //-----------------------------------------------------------------------------
 static const size_t M_OFFSET = 16;
 static const size_t M_LENGTH = 16;
@@ -96,8 +88,10 @@ static const size_t M_LENGTH = 16;
 
 //-----------------------------------------------------------------------------
 void
-MD2::update (const uint8_t *restrict data, size_t size) noexcept
+MD2::update (const void *restrict _data, size_t size) noexcept
 {
+    auto data = static_cast<const uint8_t *restrict> (_data);
+
     uint8_t *M = X + M_OFFSET;
     size_t offset = m_total % M_LENGTH;
     size_t remain = M_LENGTH - offset;
diff --git a/hash/md2.hpp b/hash/md2.hpp
index 9ac59715..3c2f6374 100644
--- a/hash/md2.hpp
+++ b/hash/md2.hpp
@@ -30,8 +30,7 @@ namespace util { namespace hash {
         public:
             MD2 ();
 
-            void update (const uint8_t *restrict data, size_t len) noexcept;
-            void update (const void    *restrict data, size_t len) noexcept;
+            void update (const void *restrict data,  size_t len) noexcept;
             void update (const uint8_t *restrict first, const uint8_t *restrict last) noexcept;
 
             void finish (void);
diff --git a/hash/md4.cpp b/hash/md4.cpp
index 6d4b4151..a396315f 100644
--- a/hash/md4.cpp
+++ b/hash/md4.cpp
@@ -100,16 +100,11 @@ MD4::update (const uint8_t *restrict first, const uint8_t *restrict last) noexce
 
 //-----------------------------------------------------------------------------
 void
-MD4::update (const void *restrict data, size_t size) noexcept
+MD4::update (const void *restrict _data, size_t size) noexcept
 {
-    update (static_cast<const uint8_t*> (data), size);
-}
+    CHECK (_data);
+    auto data = static_cast<const uint8_t *restrict> (_data);
 
-
-//-----------------------------------------------------------------------------
-void
-MD4::update (const uint8_t *restrict data, size_t size) noexcept
-{
     size_t offset = m_total % sizeof (Xb);
     size_t remain = sizeof (Xb) - offset;
 
diff --git a/hash/md4.hpp b/hash/md4.hpp
index 8c3ee9ea..dad98dee 100644
--- a/hash/md4.hpp
+++ b/hash/md4.hpp
@@ -31,7 +31,6 @@ namespace util { namespace hash {
         MD4();
 
         void update (const void    *restrict data, size_t len) noexcept;
-        void update (const uint8_t *restrict data, size_t len) noexcept;
         void update (const uint8_t *restrict first, const uint8_t *restrict last) noexcept;
 
         void finish (void);
diff --git a/hash/md5.cpp b/hash/md5.cpp
index 86368625..35ce8a29 100644
--- a/hash/md5.cpp
+++ b/hash/md5.cpp
@@ -132,16 +132,11 @@ MD5::update (const uint8_t *restrict first, const uint8_t *restrict last) noexce
 
 //-----------------------------------------------------------------------------
 void
-MD5::update (const void *restrict data, size_t len) noexcept
+MD5::update (const void *restrict _data, size_t size) noexcept
 {
-    MD5::update (static_cast<const uint8_t*> (data), len);
-}
+    CHECK (_data);
+    auto data = static_cast<const uint8_t *restrict> (_data);
 
-
-//-----------------------------------------------------------------------------
-void
-MD5::update (const uint8_t *restrict data, size_t size) noexcept
-{
     size_t offset = m_total % sizeof (Xb);
     size_t remain = sizeof (Xb) - offset;
 
diff --git a/hash/md5.hpp b/hash/md5.hpp
index 1be855d0..58679232 100644
--- a/hash/md5.hpp
+++ b/hash/md5.hpp
@@ -34,7 +34,6 @@ namespace util { namespace hash {
         MD5();
 
         void update (const void    *restrict data, size_t len) noexcept;
-        void update (const uint8_t *restrict data, size_t len) noexcept;
         void update (const uint8_t *restrict first, const uint8_t *restrict last) noexcept;
 
         void finish (void);
@@ -52,9 +51,6 @@ namespace util { namespace hash {
             uint8_t  Xb[64];
         };
     };
-
-    typedef uint8_t md5_t;
-    md5_t md5 (const void *restrict data, size_t len);
 } }
 
 #endif
diff --git a/hash/ripemd.cpp b/hash/ripemd.cpp
index b1cb6f90..2d5376bc 100644
--- a/hash/ripemd.cpp
+++ b/hash/ripemd.cpp
@@ -63,9 +63,11 @@ RIPEMD::update (
 
 //-----------------------------------------------------------------------------
 void
-RIPEMD::update (const uint8_t *restrict data, size_t len) noexcept
+RIPEMD::update (const void *restrict _data, size_t len) noexcept
 {
-    CHECK (data);
+    CHECK (_data);
+
+    auto data = static_cast<const uint8_t *restrict> (_data);
 
     size_t cursor = 0;
 
diff --git a/hash/ripemd.hpp b/hash/ripemd.hpp
index 80d964a8..1ab6db67 100644
--- a/hash/ripemd.hpp
+++ b/hash/ripemd.hpp
@@ -30,7 +30,7 @@ namespace util { namespace hash {
         public:
             RIPEMD();
 
-            void update (const uint8_t *restrict, size_t) noexcept;
+            void update (const void *restrict, size_t) noexcept;
             void update (const uint8_t *restrict first, const uint8_t *restrict last) noexcept;
 
             digest_t digest (void) const;
diff --git a/hash/sha1.cpp b/hash/sha1.cpp
index cc47b4c3..25243082 100644
--- a/hash/sha1.cpp
+++ b/hash/sha1.cpp
@@ -135,11 +135,14 @@ SHA1::update (
 
 //-----------------------------------------------------------------------------
 void
-SHA1::update (const uint8_t *restrict data, size_t size) noexcept
+SHA1::update (const void *restrict _data, size_t size) noexcept
 {
+    CHECK (_data);
     CHECK_EQ (state, READY);
     CHECK_GE (std::numeric_limits<decltype(total)>::max () - total, size);
 
+    auto data = static_cast<const uint8_t *restrict> (_data);
+
     while (size > 0) {
         // Copy the data into the remaining available buffer slots
         const size_t offset = total % BLOCK_BYTES;
diff --git a/hash/sha1.hpp b/hash/sha1.hpp
index e90d5912..022018e3 100644
--- a/hash/sha1.hpp
+++ b/hash/sha1.hpp
@@ -34,7 +34,7 @@ namespace util { namespace hash {
     public:
         SHA1();
 
-        void update (const uint8_t *restrict, size_t) noexcept;
+        void update (const void *restrict, size_t) noexcept;
         void update (const uint8_t *restrict first, const uint8_t *restrict last) noexcept;
 
         void finish (void);
diff --git a/hash/sha2.cpp b/hash/sha2.cpp
index 84f76b8d..1ff0e098 100644
--- a/hash/sha2.cpp
+++ b/hash/sha2.cpp
@@ -183,8 +183,11 @@ SHA256::update (const uint8_t *restrict first, const uint8_t *restrict last) noe
 
 //-----------------------------------------------------------------------------
 void
-SHA256::update (const uint8_t *restrict data, size_t length) noexcept
+SHA256::update (const void *restrict _data, size_t length) noexcept
 {
+    CHECK (_data);
+    auto data = static_cast<const uint8_t *restrict> (_data);
+
     while (length) {
         size_t buffered = m_total % sizeof (M);
         size_t chunk = std::min (sizeof (M) - buffered, length);
diff --git a/hash/sha2.hpp b/hash/sha2.hpp
index 0724cfd0..c72f65b6 100644
--- a/hash/sha2.hpp
+++ b/hash/sha2.hpp
@@ -31,7 +31,7 @@ namespace util { namespace hash {
     public:
         SHA256();
 
-        void update (const uint8_t *restrict, size_t) noexcept;
+        void update (const void *restrict, size_t) noexcept;
         void update (const uint8_t *restrict first, const uint8_t *restrict last) noexcept;
 
         void finish (void);