diff --git a/ghc/lib/std/PrelGHC.hi-boot b/ghc/lib/std/PrelGHC.hi-boot
index 9c8f6132a62279c49a9ca54259677cf6684336b2..bbc80a3a722bb349cae2fda640674d032ed83db1 100644
--- a/ghc/lib/std/PrelGHC.hi-boot
+++ b/ghc/lib/std/PrelGHC.hi-boot
@@ -37,6 +37,7 @@ PrelGHC
   parAtForNow#
 
   SynchVar#
+  sameMVar#
   newSynchVar#
   takeMVar#
   putMVar#