diff --git a/LayoutHints.hs b/LayoutHints.hs
index bf048d37..047d7286 100644
--- a/LayoutHints.hs
+++ b/LayoutHints.hs
@@ -1,3 +1,5 @@
+{-# LANGUAGE FlexibleInstances #-}
+
 -----------------------------------------------------------------------------
 -- |
 -- Module       : XMonadContrib.LayoutHints
diff --git a/LayoutModifier.hs b/LayoutModifier.hs
index 1320facb..8c7bd38c 100644
--- a/LayoutModifier.hs
+++ b/LayoutModifier.hs
@@ -1,3 +1,5 @@
+{-# LANGUAGE MultiParamTypeClasses #-}
+
 -----------------------------------------------------------------------------
 -- |
 -- Module       : XMonadContrib.LayoutModifier