diff --git a/ghc/lib/concurrent/Concurrent.lhs b/ghc/lib/concurrent/Concurrent.lhs
index 13a2851e61e6be666cf719c3283c5be49242c282..132922ef45ea6e6411431d560777032239b7f0f4 100644
--- a/ghc/lib/concurrent/Concurrent.lhs
+++ b/ghc/lib/concurrent/Concurrent.lhs
@@ -56,6 +56,7 @@ import Channel
 import Semaphore
 import SampleVar
 import PrelConc
+import PrelHandle       ( topHandler )
 import PrelException
 import PrelIOBase	( IO(..) )
 import IO