diff --git a/src/compiler/GF/Data/BacktrackM.hs b/src/compiler/GF/Data/BacktrackM.hs
index 36317ebb6..4e84022f4 100644
--- a/src/compiler/GF/Data/BacktrackM.hs
+++ b/src/compiler/GF/Data/BacktrackM.hs
@@ -12,7 +12,7 @@
 -- Backtracking state monad, with r\/o environment
 -----------------------------------------------------------------------------
 
-{-# OPTIONS_GHC -fglasgow-exts #-}
+{-# LANGUAGE Rank2Types, MultiParamTypeClasses, FlexibleInstances #-}
 module GF.Data.BacktrackM (
                     -- * the backtracking state monad
 		    BacktrackM,
diff --git a/src/runtime/haskell/Data/Binary/Get.hs b/src/runtime/haskell/Data/Binary/Get.hs
index 51062ad31..728720b3e 100644
--- a/src/runtime/haskell/Data/Binary/Get.hs
+++ b/src/runtime/haskell/Data/Binary/Get.hs
@@ -1,5 +1,4 @@
-{-# LANGUAGE CPP #-}
-{-# OPTIONS_GHC -fglasgow-exts #-}
+{-# LANGUAGE CPP, MagicHash #-}
 -- for unboxed shifts
 
 -----------------------------------------------------------------------------