diff --git a/gen/Gen.hs b/gen/Gen.hs
index c570bc2..a6c98d2 100644
--- a/gen/Gen.hs
+++ b/gen/Gen.hs
@@ -13,34 +13,34 @@ data GenHashModule = GenHashModule
     { ghmModuleName   :: String
     , ghmHeaderFile   :: String
     , ghmHashName     :: String
-    , ghmContextSize  :: Int
-    , ghmDigestSize   :: Int
-    , ghmBlockLength  :: Int
-    , ghmCustomizable :: [(Int, Int)]
+    , ghmContextSize  :: Int -- in bytes
+    , ghmDigestSize   :: Int -- in bytes
+    , ghmBlockLength  :: Int -- in bytes
+    , ghmCustomizable :: [(Int, Int)] -- list of (digest output size in *bits*, block size in bytes)
     } deriving (Show,Eq)
 
 hashModules =
     --              module      header        hash        ctx dg blk
-    [ GenHashModule "BLAKE2s"   "blake2.h"    "blake2s"   185 32 64  []
-    , GenHashModule "BLAKE2sp"  "blake2.h"    "blake2sp"  2185 32 64 []
-    , GenHashModule "BLAKE2b"   "blake2.h"    "blake2b"   361 64 128 []
-    , GenHashModule "BLAKE2bp"  "blake2.h"    "blake2sp"  2325 64 128 []
-    , GenHashModule "MD2"       "md2.h"       "md2"       96  16 16  []
-    , GenHashModule "MD4"       "md4.h"       "md4"       96  16 64  []
-    , GenHashModule "MD5"       "md5.h"       "md5"       96  16 64  []
-    , GenHashModule "SHA1"      "sha1.h"      "sha1"      96  20 64  []
-    , GenHashModule "SHA224"    "sha256.h"    "sha224"    192 28 64  []
-    , GenHashModule "SHA256"    "sha256.h"    "sha256"    192 32 64  []
-    , GenHashModule "SHA384"    "sha512.h"    "sha384"    256 48 128 []
-    , GenHashModule "SHA512"    "sha512.h"    "sha512"    256 64 128 []
-    , GenHashModule "SHA512t"   "sha512.h"    "sha512t"   264 64 128 [(224,128),(256,128)]
-    , GenHashModule "Keccak"    "keccak.h"    "keccak"    360 64 64  [(224,144),(256,136),(384,104),(512,72)]
-    , GenHashModule "SHA3"      "sha3.h"      "sha3"      360 64 64  [(224,144),(256,136),(384,104),(512,72)]
-    , GenHashModule "RIPEMD160" "ripemd.h"    "ripemd160" 128 20 64  []
-    , GenHashModule "Skein256"  "skein256.h"  "skein256"  96  32 32  [(224,32),(256,32)]
-    , GenHashModule "Skein512"  "skein512.h"  "skein512"  160 64 64  [(224,64),(256,64),(384,64),(512,64)]
-    , GenHashModule "Tiger"     "tiger.h"     "tiger"     96  24 64  []
-    , GenHashModule "Whirlpool" "whirlpool.h" "whirlpool" 168 64 64  []
+    [ GenHashModule "BLAKE2s"   "blake2.h"    "blake2s"   185 256 64  []
+    , GenHashModule "BLAKE2sp"  "blake2.h"    "blake2sp"  2185 256 64 []
+    , GenHashModule "BLAKE2b"   "blake2.h"    "blake2b"   361 512 128 []
+    , GenHashModule "BLAKE2bp"  "blake2.h"    "blake2sp"  2325 512 128 []
+    , GenHashModule "MD2"       "md2.h"       "md2"       96  128 16  []
+    , GenHashModule "MD4"       "md4.h"       "md4"       96  128 64  []
+    , GenHashModule "MD5"       "md5.h"       "md5"       96  128 64  []
+    , GenHashModule "SHA1"      "sha1.h"      "sha1"      96  160 64  []
+    , GenHashModule "SHA224"    "sha256.h"    "sha224"    192 224 64  []
+    , GenHashModule "SHA256"    "sha256.h"    "sha256"    192 256 64  []
+    , GenHashModule "SHA384"    "sha512.h"    "sha384"    256 384 128 []
+    , GenHashModule "SHA512"    "sha512.h"    "sha512"    256 512 128 []
+    , GenHashModule "SHA512t"   "sha512.h"    "sha512t"   264 512 128 [(224,128),(256,128)]
+    , GenHashModule "Keccak"    "keccak.h"    "keccak"    360 512 64  [(224,144),(256,136),(384,104),(512,72)]
+    , GenHashModule "SHA3"      "sha3.h"      "sha3"      360 512 64  [(224,144),(256,136),(384,104),(512,72)]
+    , GenHashModule "RIPEMD160" "ripemd.h"    "ripemd160" 128 160 64  []
+    , GenHashModule "Skein256"  "skein256.h"  "skein256"  96  256 32  [(224,32),(256,32)]
+    , GenHashModule "Skein512"  "skein512.h"  "skein512"  160 512 64  [(224,64),(256,64),(384,64),(512,64)]
+    , GenHashModule "Tiger"     "tiger.h"     "tiger"     96  192 64  []
+    , GenHashModule "Whirlpool" "whirlpool.h" "whirlpool" 168 512 64  []
     ]
 
 renderHashModules genOpts = do
@@ -54,13 +54,13 @@ renderHashModules genOpts = do
                    -- context size (compat)
                    , ("SIZECTX"          , show (ghmContextSize ghm))
                    , ("SIZECTX8"         , show (ghmContextSize ghm `div` 8))
-                   , ("DIGESTSIZE"       , show (ghmDigestSize ghm))
+                   , ("DIGESTSIZE"       , show (ghmDigestSize ghm `div` 8))
                    , ("BLOCKLEN"         , show (ghmBlockLength ghm))
                    -- context size
                    , ("CTX_SIZE_BYTES"   , show (ghmContextSize ghm))
                    , ("CTX_SIZE_WORD64"  , show (ghmContextSize ghm `div` 8))
-                   , ("DIGEST_SIZE_BITS" , show (ghmDigestSize ghm * 8))
-                   , ("DIGEST_SIZE_BYTES", show (ghmDigestSize ghm))
+                   , ("DIGEST_SIZE_BITS" , show (ghmDigestSize ghm))
+                   , ("DIGEST_SIZE_BYTES", show (ghmDigestSize ghm `div` 8))
                    , ("BLOCK_SIZE_BYTES" , show (ghmBlockLength ghm))
                    ] :: Attrs
         let mainDir      = "Crypto/Hash"
diff --git a/gen/template/hash.hs b/gen/template/hash.hs
index 6fa0431..0ab2eae 100644
--- a/gen/template/hash.hs
+++ b/gen/template/hash.hs
@@ -20,9 +20,9 @@ data %%MODULENAME%% = %%MODULENAME%%
     deriving (Show)
 
 instance HashAlgorithm %%MODULENAME%% where
-    hashBlockSize  _          = %%BLOCKLEN%%
-    hashDigestSize _          = %%DIGESTSIZE%%
-    hashInternalContextSize _ = %%SIZECTX%%
+    hashBlockSize  _          = %%BLOCK_SIZE_BYTES%%
+    hashDigestSize _          = %%DIGEST_SIZE_BYTES%%
+    hashInternalContextSize _ = %%CTX_SIZE_BYTES%%
     hashInternalInit          = c_%%HASHNAME%%_init
     hashInternalUpdate        = c_%%HASHNAME%%_update
     hashInternalFinalize      = c_%%HASHNAME%%_finalize