diff --git a/ghc/tests/ccall/should_fail/cc004.stderr b/ghc/tests/ccall/should_fail/cc004.stderr
index 49faa6731678a6f63ce3dcb1e66d508c087440dd..11636db691d5771c968620a2e2215e04c6028da0 100644
--- a/ghc/tests/ccall/should_fail/cc004.stderr
+++ b/ghc/tests/ccall/should_fail/cc004.stderr
@@ -5,7 +5,7 @@ cc004.hs:2:
 
 cc004.hs:2:
     Cannot generalise these overloadings (in a _ccall_):
-	`CReturnable t_a1d4' arising from the result of the _ccall_ to `f' at cc004.hs:15
+	`CReturnable t_aJo' arising from the result of the _ccall_ to `f' at cc004.hs:15
 
 Compilation had errors