diff --git a/ghc/compiler/typecheck/TcExpr.lhs b/ghc/compiler/typecheck/TcExpr.lhs
index b9960e6c2df44397461cf33d35106a1487bc3e72..32a2eb23f039e0cb4ca50ef6af051650e13a2397 100644
--- a/ghc/compiler/typecheck/TcExpr.lhs
+++ b/ghc/compiler/typecheck/TcExpr.lhs
@@ -143,7 +143,7 @@ tcPolyExpr arg expected_arg_ty
     newDicts SignatureOrigin sig_theta		`thenNF_Tc` \ (sig_dicts, dict_ids) ->
 	-- ToDo: better origin
     tcSimplifyAndCheck 
-	(text "tcPolyExpr")
+	(text "the type signature of an expression")
 	(mkVarSet zonked_sig_tyvars)
 	sig_dicts lie_arg			`thenTc` \ (free_insts, inst_binds) ->