diff --git a/src/Data/Gram.hs b/src/Data/Gram.hs
index 319c0049d..782f609fb 100644
--- a/src/Data/Gram.hs
+++ b/src/Data/Gram.hs
@@ -16,16 +16,13 @@ serialize gram = stem gram <> base gram
 type Bag = DList
 
 
-featureVector :: Hashable label => Bag (Gram label) -> Int -> Vector Rational
+featureVector :: Hashable label => Bag (Gram label) -> Int -> Vector Double
 featureVector bag d = sumVectors $ unitDVector . hash <$> bag
   where unitDVector hash = normalize . (`evalRand` mkQCGen hash) $ Prologue.sequence (Vector.replicate d getRandom)
         normalize vec = fmap (/ magnitude vec) vec
-        magnitude vec = toRational (sqrtDouble (fromRational (Vector.sum (fmap (^^ (2 :: Integer)) vec))))
+        magnitude vec = sqrtDouble (Vector.sum (fmap (** 2) vec))
         sumVectors = DList.foldr (Vector.zipWith (+)) (Vector.replicate d 0)
 
 instance Hashable label => Hashable (Gram label) where
   hashWithSalt _ = hash
   hash = hash . serialize
-
-instance (Random a, Integral a) => Random (Ratio a) where
-  random = first (% 1) . random