diff --git a/src/Weeder.hs b/src/Weeder.hs
index f8e0055..e2def12 100644
--- a/src/Weeder.hs
+++ b/src/Weeder.hs
@@ -25,9 +25,11 @@ module Weeder
   )
   where
 
+-- algebraic-graphs
 import Algebra.Graph ( Graph, edge, empty, overlay, vertex, vertexList )
 import Algebra.Graph.ToGraph ( dfs )
 
+-- base
 import Control.Applicative ( Alternative )
 import Control.Monad ( guard, msum, when )
 import Data.Foldable ( for_, traverse_ )
@@ -36,12 +38,17 @@ import Data.Monoid ( First( First ) )
 import GHC.Generics ( Generic )
 import Prelude hiding ( span )
 
+-- containers
 import Data.Map.Strict ( Map )
 import qualified Data.Map.Strict as Map
 import Data.Sequence ( Seq )
 import Data.Set ( Set )
 import qualified Data.Set as Set
 
+-- generic-lens
+import Data.Generics.Labels ()
+
+-- ghc
 import Avail ( AvailInfo( Avail, AvailTC ) )
 import FieldLabel ( FieldLbl( FieldLabel, flSelector ) )
 import HieTypes
@@ -68,12 +75,13 @@ import OccName
   )
 import SrcLoc ( RealSrcSpan, realSrcSpanStart, realSrcSpanEnd )
 
-import Data.Generics.Labels ()
-
+-- lens
 import Control.Lens ( (%=) )
 
+-- mtl
 import Control.Monad.State.Class ( MonadState )
 
+-- transformers
 import Control.Monad.Trans.Maybe ( runMaybeT )
 
 
diff --git a/src/Weeder/Config.hs b/src/Weeder/Config.hs
index 2fc78a5..6dea9ca 100644
--- a/src/Weeder/Config.hs
+++ b/src/Weeder/Config.hs
@@ -5,8 +5,14 @@
 
 module Weeder.Config where
 
+-- containers
+import Data.Set ( Set )
+import qualified Data.Set as Set
+
+-- dhall
 import qualified Dhall
-import Weeder
+
+-- ghc
 import Module
   ( DefUnitId( DefUnitId )
   , Module( Module )
@@ -18,8 +24,9 @@ import OccName
   ( mkOccName
   , varName
   )
-import Data.Set ( Set )
-import qualified Data.Set as Set
+
+-- weeder
+import Weeder
 
 
 -- | Configuration for Weeder analysis.
diff --git a/src/Weeder/Main.hs b/src/Weeder/Main.hs
index f02f74f..e8a26fb 100644
--- a/src/Weeder/Main.hs
+++ b/src/Weeder/Main.hs
@@ -8,16 +8,26 @@
 
 module Weeder.Main ( main, mainWithConfig ) where
 
+-- base
 import Control.Monad ( guard )
 import Control.Monad.IO.Class ( liftIO )
+import Data.Bool
+import Data.Foldable
 
+-- containers
 import qualified Data.Map.Strict as Map
 import qualified Data.Set as Set
 
+-- dhall
+import qualified Dhall
+
+-- directory
 import System.Directory ( doesPathExist, withCurrentDirectory, canonicalizePath, listDirectory, doesFileExist, doesDirectoryExist )
 
+-- filepath
 import System.FilePath ( isExtensionOf )
 
+-- ghc
 import HieBin ( HieFileResult( HieFileResult, hie_file_result ) )
 import HieBin ( readHieFile )
 import NameCache ( initNameCache )
@@ -25,14 +35,15 @@ import OccName ( occNameString )
 import SrcLoc ( srcLocLine, srcLocCol, realSrcSpanStart )
 import UniqSupply ( mkSplitUniqSupply )
 
+-- optparse-applicative
+import Options.Applicative
+
+-- transformers
 import Control.Monad.Trans.State.Strict ( execStateT )
 
+-- weeder
 import Weeder
 import Weeder.Config
-import qualified Dhall
-import Options.Applicative
-import Data.Foldable
-import Data.Bool
 
 
 main :: IO ()