diff --git a/Data/Aeson/Encode.hs b/Data/Aeson/Encode.hs
--- a/Data/Aeson/Encode.hs
+++ b/Data/Aeson/Encode.hs
@@ -34,9 +34,10 @@
 
 import Data.Aeson.Types (Value(..))
 import Data.Monoid (mappend)
-import Data.Scientific (Scientific, coefficient, base10Exponent, scientificBuilder)
+import Data.Scientific (Scientific, coefficient, base10Exponent)
 import Data.Text.Lazy.Builder
 import Data.Text.Lazy.Builder.Int (decimal)
+import Data.Text.Lazy.Builder.Scientific (scientificBuilder)
 import Numeric (showHex)
 import qualified Data.HashMap.Strict as H
 import qualified Data.Text as T
diff --git a/Data/Aeson/Encode/ByteString.hs b/Data/Aeson/Encode/ByteString.hs
--- a/Data/Aeson/Encode/ByteString.hs
+++ b/Data/Aeson/Encode/ByteString.hs
@@ -19,11 +19,12 @@
 import Prelude hiding (null)
 import Data.Aeson.Types (ToJSON(..), Value(..))
 import Data.Char (ord)
-import Data.Scientific (Scientific, coefficient, base10Exponent, formatScientific, FPFormat(Generic))
+import Data.Scientific (Scientific, coefficient, base10Exponent)
 import Data.Word (Word8)
 import Data.Monoid (mappend)
 import           Data.ByteString.Builder      as B
 import           Data.ByteString.Builder.Prim as BP
+import           Data.ByteString.Builder.Scientific (scientificBuilder)
 import qualified Data.ByteString.Lazy as L
 import qualified Data.HashMap.Strict as HMS
 import qualified Data.Text as T
@@ -95,7 +96,7 @@
 
 number :: Scientific -> Builder
 number s
-    | e < 0     = B.string8 $ formatScientific Generic Nothing s
+    | e < 0     = scientificBuilder s
     | otherwise = B.integerDec (coefficient s * 10 ^ e)
   where
     e = base10Exponent s
diff --git a/Data/Aeson/Types/Instances.hs b/Data/Aeson/Types/Instances.hs
--- a/Data/Aeson/Types/Instances.hs
+++ b/Data/Aeson/Types/Instances.hs
@@ -56,7 +56,7 @@
 import Data.Aeson.Types.Class
 import Data.Aeson.Types.Internal
 import Data.Scientific (Scientific)
-import qualified Data.Scientific as Scientific (coefficient, base10Exponent, fromFloatDigits)
+import qualified Data.Scientific as Scientific (coefficient, base10Exponent, fromFloatDigits, toRealFloat)
 import Data.Attoparsec.Number (Number(..))
 import Data.Fixed
 import Data.Hashable (Hashable(..))
@@ -167,16 +167,8 @@
     toJSON = realFloatToJSON
     {-# INLINE toJSON #-}
 
-realFloatToJSON :: RealFloat a => a -> Value
-realFloatToJSON d
-    | isNaN d || isInfinite d = Null
-    | otherwise = Number $ Scientific.fromFloatDigits d
-{-# INLINE realFloatToJSON #-}
-
 instance FromJSON Double where
-    parseJSON (Number s) = pure $ realToFrac s
-    parseJSON Null       = pure (0/0)
-    parseJSON v          = typeMismatch "Double" v
+    parseJSON = parseRealFloat "Double"
     {-# INLINE parseJSON #-}
 
 instance ToJSON Number where
@@ -195,9 +187,7 @@
     {-# INLINE toJSON #-}
 
 instance FromJSON Float where
-    parseJSON (Number s) = pure $ realToFrac s
-    parseJSON Null       = pure (0/0)
-    parseJSON v          = typeMismatch "Float" v
+    parseJSON = parseRealFloat "Float"
     {-# INLINE parseJSON #-}
 
 instance ToJSON (Ratio Integer) where
@@ -216,6 +206,10 @@
     toJSON = Number . realToFrac
     {-# INLINE toJSON #-}
 
+-- | /WARNING:/ Only parse fixed-precision numbers from trusted input
+-- since an attacker could easily fill up the memory of the target
+-- system by specifying a scientific number with a big exponent like
+-- @1e1000000000@.
 instance HasResolution a => FromJSON (Fixed a) where
     parseJSON = withScientific "Fixed" $ pure . realToFrac
     {-# INLINE parseJSON #-}
@@ -225,19 +219,19 @@
     {-# INLINE toJSON #-}
 
 instance FromJSON Int where
-    parseJSON = parseIntegral
+    parseJSON = parseIntegral "Int"
     {-# INLINE parseJSON #-}
 
-parseIntegral :: Integral a => Value -> Parser a
-parseIntegral = withScientific "Integral" $ pure . floor
-{-# INLINE parseIntegral #-}
-
 instance ToJSON Integer where
     toJSON = Number . fromInteger
     {-# INLINE toJSON #-}
 
+-- | /WARNING:/ Only parse Integers from trusted input since an
+-- attacker could easily fill up the memory of the target system by
+-- specifying a scientific number with a big exponent like
+-- @1e1000000000@.
 instance FromJSON Integer where
-    parseJSON = parseIntegral
+    parseJSON = withScientific "Integral" $ pure . floor
     {-# INLINE parseJSON #-}
 
 instance ToJSON Int8 where
@@ -245,7 +239,7 @@
     {-# INLINE toJSON #-}
 
 instance FromJSON Int8 where
-    parseJSON = parseIntegral
+    parseJSON = parseIntegral "Int8"
     {-# INLINE parseJSON #-}
 
 instance ToJSON Int16 where
@@ -253,7 +247,7 @@
     {-# INLINE toJSON #-}
 
 instance FromJSON Int16 where
-    parseJSON = parseIntegral
+    parseJSON = parseIntegral "Int16"
     {-# INLINE parseJSON #-}
 
 instance ToJSON Int32 where
@@ -261,7 +255,7 @@
     {-# INLINE toJSON #-}
 
 instance FromJSON Int32 where
-    parseJSON = parseIntegral
+    parseJSON = parseIntegral "Int32"
     {-# INLINE parseJSON #-}
 
 instance ToJSON Int64 where
@@ -269,7 +263,7 @@
     {-# INLINE toJSON #-}
 
 instance FromJSON Int64 where
-    parseJSON = parseIntegral
+    parseJSON = parseIntegral "Int64"
     {-# INLINE parseJSON #-}
 
 instance ToJSON Word where
@@ -277,7 +271,7 @@
     {-# INLINE toJSON #-}
 
 instance FromJSON Word where
-    parseJSON = parseIntegral
+    parseJSON = parseIntegral "Word"
     {-# INLINE parseJSON #-}
 
 instance ToJSON Word8 where
@@ -285,7 +279,7 @@
     {-# INLINE toJSON #-}
 
 instance FromJSON Word8 where
-    parseJSON = parseIntegral
+    parseJSON = parseIntegral "Word8"
     {-# INLINE parseJSON #-}
 
 instance ToJSON Word16 where
@@ -293,7 +287,7 @@
     {-# INLINE toJSON #-}
 
 instance FromJSON Word16 where
-    parseJSON = parseIntegral
+    parseJSON = parseIntegral "Word16"
     {-# INLINE parseJSON #-}
 
 instance ToJSON Word32 where
@@ -301,7 +295,7 @@
     {-# INLINE toJSON #-}
 
 instance FromJSON Word32 where
-    parseJSON = parseIntegral
+    parseJSON = parseIntegral "Word32"
     {-# INLINE parseJSON #-}
 
 instance ToJSON Word64 where
@@ -309,7 +303,7 @@
     {-# INLINE toJSON #-}
 
 instance FromJSON Word64 where
-    parseJSON = parseIntegral
+    parseJSON = parseIntegral "Word64"
     {-# INLINE parseJSON #-}
 
 instance ToJSON Text where
@@ -788,11 +782,27 @@
              Bool _   -> "Boolean"
              Null     -> "Null"
 
+realFloatToJSON :: RealFloat a => a -> Value
+realFloatToJSON d
+    | isNaN d || isInfinite d = Null
+    | otherwise = Number $ Scientific.fromFloatDigits d
+{-# INLINE realFloatToJSON #-}
+
 scientificToNumber :: Scientific -> Number
 scientificToNumber s
-    | e < 0     = D $ realToFrac s
+    | e < 0     = D $ Scientific.toRealFloat s
     | otherwise = I $ c * 10 ^ e
   where
     e = Scientific.base10Exponent s
     c = Scientific.coefficient s
 {-# INLINE scientificToNumber #-}
+
+parseRealFloat :: RealFloat a => String -> Value -> Parser a
+parseRealFloat _        (Number s) = pure $ Scientific.toRealFloat s
+parseRealFloat _        Null       = pure (0/0)
+parseRealFloat expected v          = typeMismatch expected v
+{-# INLINE parseRealFloat #-}
+
+parseIntegral :: Integral a => String -> Value -> Parser a
+parseIntegral expected = withScientific expected $ pure . floor
+{-# INLINE parseIntegral #-}
diff --git a/aeson.cabal b/aeson.cabal
--- a/aeson.cabal
+++ b/aeson.cabal
@@ -1,5 +1,5 @@
 name:            aeson
-version:         0.7.0.4
+version:         0.7.0.5
 license:         BSD3
 license-file:    LICENSE
 category:        Text, Web, JSON
@@ -112,14 +112,14 @@
       Data.Aeson.Types.Generic
 
   build-depends:
-    attoparsec >= 0.10.2.1,
+    attoparsec >= 0.11.3.4,
     base == 4.*,
     containers,
     deepseq,
     hashable >= 1.1.2.0,
     mtl,
     old-locale,
-    scientific >= 0.2 && < 0.3,
+    scientific >= 0.3.1 && < 0.4,
     syb,
     template-haskell >= 2.4,
     time,