diff --git a/ghc/compiler/utils/FastString.lhs b/ghc/compiler/utils/FastString.lhs
index 5c8e3f122ac2b2786ef3fcf61d28e360d0606cf6..e9624be6d9c2d6d530e4434b18b2863abb5aa774 100644
--- a/ghc/compiler/utils/FastString.lhs
+++ b/ghc/compiler/utils/FastString.lhs
@@ -62,7 +62,7 @@ import PackBase
 #endif
 #if __GLASGOW_HASKELL__ >= 209
 import Addr
-import IORef
+import IOExts
 # define newVar   newIORef
 # define readVar  readIORef
 # define writeVar writeIORef