diff --git a/lib/Echidna/.Exec.hs.swp b/lib/Echidna/.Exec.hs.swp
new file mode 100644
index 00000000..1f928520
Binary files /dev/null and b/lib/Echidna/.Exec.hs.swp differ
diff --git a/lib/Echidna/Config.hs b/lib/Echidna/Config.hs
index b0d0d351..6f390612 100644
--- a/lib/Echidna/Config.hs
+++ b/lib/Echidna/Config.hs
@@ -1,46 +1,42 @@
-{-# LANGUAGE DeriveGeneric, FlexibleContexts, TemplateHaskell #-}
+{-# LANGUAGE FlexibleContexts, TemplateHaskell #-}
 
 module Echidna.Config where
 
 import Control.Monad.Catch    (MonadThrow(..))
 import Control.Monad.IO.Class (MonadIO(..))
+import Control.Monad.Reader   (ReaderT, runReaderT)
 import Control.Lens
 import Control.Exception      (Exception)
-import Control.Monad.Reader   (ReaderT, runReaderT)
 import Data.Aeson
-import GHC.Generics
 
 import qualified Data.ByteString.Char8 as BS
 import qualified Data.Yaml as Y
 
 import EVM.Types (W256)
 
-
 data Config = Config
   { _solcArgs :: Maybe String
   , _epochs :: Int
   , _testLimit :: Int
   , _range :: Int
   , _gasLimit :: W256 }
-  deriving (Show, Generic)
+  deriving Show
 
 makeLenses ''Config
 
-instance FromJSON Config
-
-defaultConfig :: Config
-defaultConfig = Config
-  { _solcArgs = Nothing
-  , _epochs = 2
-  , _testLimit = 10000
-  , _range = 10
-  , _gasLimit = 0xffffffffffffffff }
-
-withDefaultConfig :: ReaderT Config m a -> m a
-withDefaultConfig = (flip runReaderT) defaultConfig
+instance FromJSON Config where
+  parseJSON (Object v) = Config <$> v .:? "solcArgs"  .!= Nothing
+                                <*> v .:? "epochs"    .!= 2
+                                <*> v .:? "testLimit" .!= 10000
+                                <*> v .:? "range"     .!= 10
+                                <*> v .:? "gasLimit"  .!= 0xffffffffffffffff 
+  parseJSON _          = parseJSON (Object mempty)
 
 data ParseException = ParseException FilePath
 
+defaultConfig :: Config
+defaultConfig = either (error "Config parser got messed up :(") id $ Y.decodeEither ""
+
 instance Show ParseException where
   show (ParseException f) = "Could not parse config file " ++ (show f)
 
@@ -48,8 +44,11 @@ instance Exception ParseException
 
 parseConfig :: (MonadThrow m, MonadIO m) => FilePath -> m Config
 parseConfig file = do
-    content <- liftIO $ BS.readFile file
-    let parsedContent = Y.decode content :: Maybe Config
-    case parsedContent of
-        Nothing -> throwM (ParseException file)
-        (Just c) -> return c  
+  content <- liftIO $ BS.readFile file
+  let parsedContent = Y.decode content :: Maybe Config
+  case parsedContent of
+    Nothing  -> throwM (ParseException file)
+    (Just c) -> return c
+
+withDefaultConfig :: ReaderT Config m a -> m a
+withDefaultConfig = (`runReaderT` defaultConfig)
diff --git a/lib/Echidna/Solidity.hs b/lib/Echidna/Solidity.hs
index bec11413..92bce2b3 100644
--- a/lib/Echidna/Solidity.hs
+++ b/lib/Echidna/Solidity.hs
@@ -8,7 +8,7 @@ import Control.Exception          (Exception)
 import Control.Monad              (liftM2)
 import Control.Monad.Catch        (MonadThrow(..))
 import Control.Monad.IO.Class     (MonadIO(..))
-import Control.Monad.Reader       (MonadReader, ask, runReaderT)
+import Control.Monad.Reader       (MonadReader, ask)
 import Control.Monad.State.Strict (MonadState, execState, modify, runState)
 import Data.Foldable              (toList)
 import Data.List                  (find, partition)
@@ -22,7 +22,7 @@ import System.IO.Temp             (writeSystemTempFile)
 import qualified Data.Map as Map (lookup)
 
 import Echidna.ABI    (SolSignature)
-import Echidna.Config (Config(..), gasLimit, solcArgs, defaultConfig)
+import Echidna.Config (Config(..), gasLimit, solcArgs)
 
 import EVM
   (Contract, VM, VMResult(..), contract, contracts, env, gas, loadContract, replaceCodeOfSelf, resetState, state)
@@ -114,6 +114,5 @@ currentContract :: MonadThrow m => VM -> m Contract
 currentContract v = let a = v ^. state . contract in
   maybe (throwM $ BadAddr a) pure . Map.lookup a $ v ^. env . contracts
 
-
-addSolidity :: (MonadIO m, MonadThrow m, MonadState VM m) => FilePath -> Maybe Text -> m ()
-addSolidity f mc = insertContract =<< currentContract =<< view _1 <$> runReaderT (loadSolidity f mc) defaultConfig
+addSolidity :: (MonadIO m, MonadReader Config m, MonadState VM m, MonadThrow m) => FilePath -> Maybe Text -> m ()
+addSolidity f mc = insertContract =<< currentContract =<< view _1 <$> loadSolidity f mc
diff --git a/solidity/config.yaml b/solidity/config.yaml
index 15c7f7c4..a1a7a4ae 100644
--- a/solidity/config.yaml
+++ b/solidity/config.yaml
@@ -1,4 +1,2 @@
-_epochs: 2
-_gasLimit: 0xfffff
-_testLimit: 10000
-_range: 10
\ No newline at end of file
+epochs: 3
+range: 20