diff --git a/driver/Main.hs b/driver/Main.hs
--- a/driver/Main.hs
+++ b/driver/Main.hs
@@ -13,8 +13,8 @@
 import           Paths_hpack (version)
 import           Run
 
-header :: String -> String
-header configFile = unlines [
+header :: String
+header = unlines [
     "-- This file has been generated from " ++ configFile ++ " by hpack version " ++ showVersion version ++ "."
   , "--"
   , "-- see: https://github.com/sol/hpack"
@@ -23,10 +23,10 @@
 
 main :: IO ()
 main = do
-  (configFile, warnings, name, new) <- run
+  (warnings, name, new) <- run
   forM_ warnings $ \warning -> hPutStrLn stderr ("WARNING: " ++ warning)
   old <- force . either (const Nothing) (Just . stripHeader) <$> tryJust (guard . isDoesNotExistError) (readFile name)
-  unless (old == Just (lines new)) (writeFile name $ header configFile ++ new)
+  unless (old == Just (lines new)) (writeFile name $ header ++ new)
   where
     stripHeader :: String -> [String]
     stripHeader = dropWhile null . dropWhile ("--" `isPrefixOf`) . lines
diff --git a/hpack.cabal b/hpack.cabal
--- a/hpack.cabal
+++ b/hpack.cabal
@@ -1,9 +1,9 @@
--- This file has been generated from package.yml by hpack version 0.2.0.
+-- This file has been generated from package.yaml by hpack version 0.3.0.
 --
 -- see: https://github.com/sol/hpack
 
 name:           hpack
-version:        0.2.0
+version:        0.3.0
 synopsis:       An alternative format for Haskell packages
 homepage:       https://github.com/sol/hpack#readme
 bug-reports:    https://github.com/sol/hpack/issues
diff --git a/src/Run.hs b/src/Run.hs
--- a/src/Run.hs
+++ b/src/Run.hs
@@ -1,6 +1,7 @@
 {-# LANGUAGE QuasiQuotes, RecordWildCards #-}
 module Run (
   run
+, configFile
 -- exported for testing
 , renderPackage
 ) where
@@ -15,9 +16,9 @@
 import           Config
 
 configFile :: FilePath
-configFile = "package.yml"
+configFile = "package.yaml"
 
-run :: IO (FilePath, [String], FilePath, String)
+run :: IO ([String], FilePath, String)
 run = do
   mPackage <- readPackageConfig configFile
   case mPackage of
@@ -28,7 +29,7 @@
 
       let alignment = fromMaybe 16 (old >>= sniffAlignment)
           output = renderPackage alignment (maybe [] extractFieldOrderHint old) package
-      return (configFile, warnings, cabalFile, output)
+      return (warnings, cabalFile, output)
     Left err -> die err
 
 renderPackage :: Int -> [String] -> Package -> String
diff --git a/test/ConfigSpec.hs b/test/ConfigSpec.hs
--- a/test/ConfigSpec.hs
+++ b/test/ConfigSpec.hs
@@ -441,7 +441,7 @@
         Right (_, c) <- readPackageConfig "package.yml"
         c `shouldBe` package {packageTests = [(executable "spec" "test/Spec.hs") {executableDependencies = [["hspec", "QuickCheck"]]}]}
 
-      context "when both top-level and section specific dependencies are specified" $ do
+      context "when both global and section specific dependencies are specified" $ do
         it "combines dependencies" $ do
           writeFile "package.yml" [i|
             dependencies: