diff --git a/Bustle/Noninteractive.hs b/Bustle/Noninteractive.hs
index 56e5d74..48d9461 100644
--- a/Bustle/Noninteractive.hs
+++ b/Bustle/Noninteractive.hs
@@ -25,7 +25,7 @@ where
 
 import Prelude hiding (log)
 
-import System
+import System.Exit (exitFailure)
 import System.IO (hPutStrLn, stderr)
 import Data.Maybe (fromMaybe, mapMaybe)
 import Data.List (nub)
diff --git a/Bustle/Stats.hs b/Bustle/Stats.hs
index 8a3e206..d822058 100644
--- a/Bustle/Stats.hs
+++ b/Bustle/Stats.hs
@@ -68,7 +68,7 @@ frequencies = reverse
     where alt Nothing  = Just 1
           alt (Just n) = Just (n + 1)
 
-mean :: Fractional a => [a] -> a
+mean :: (Eq a, Fractional a) => [a] -> a
 mean = acc 0 0
    where acc 0 _ [] = error "mean of empty list"
          acc n t [] = t / n
diff --git a/bustle.cabal b/bustle.cabal
index 93b16bd..cd47efa 100644
--- a/bustle.cabal
+++ b/bustle.cabal
@@ -94,7 +94,6 @@ Executable bustle
                  , glade
                  , glib
                  , gtk > 0.11
-                 , haskell98
                  , mtl
                  , pango
                  , parsec
@@ -114,7 +113,6 @@ Executable bustle
                  , glade
                  , glib
                  , gtk > 0.10 && < 0.11
-                 , haskell98
                  , mtl
                  , pango
                  , parsec