diff --git a/CHANGELOG.md b/CHANGELOG.md
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,8 @@
 # Changelog
 
+- 0.3.1.0 (2016-10-18)
+    * Fix compilation with `lts-6.22`.
+
 - 0.3.0.0 (2016-10-17)
     * Add syntax highlighting support.
     * Fixed slide clipping after reload.
diff --git a/patat.cabal b/patat.cabal
--- a/patat.cabal
+++ b/patat.cabal
@@ -1,5 +1,5 @@
 Name:                patat
-Version:             0.3.0.0
+Version:             0.3.1.0
 Synopsis:            Terminal-based presentations using Pandoc
 Description:         Terminal-based presentations using Pandoc
 License:             GPL-2
diff --git a/src/Patat/Theme.hs b/src/Patat/Theme.hs
--- a/src/Patat/Theme.hs
+++ b/src/Patat/Theme.hs
@@ -255,6 +255,7 @@
     unCapitalize (x : xs) = toLower x : xs
     unCapitalize xs       = xs
 
+    dropTok :: String -> String
     dropTok str
         | "Tok" `isSuffixOf` str = take (length str - 3) str
         | otherwise              = str