diff --git a/src/lib/CoAlgMisc.ml b/src/lib/CoAlgMisc.ml
index 6b1e98eb3b52ff75a1b58c0674ed4dae0b396143..8c062fe0f7069aad60cfd046036d28087226fa19 100644
--- a/src/lib/CoAlgMisc.ml
+++ b/src/lib/CoAlgMisc.ml
@@ -792,7 +792,8 @@ let rec detClosure nomTbl hcF fset atset nomset s f =
     let (func, sortlst) = !sortTable.(s) in
     match f.HC.node with
     | C.HCTRUE
-    | C.HCFALSE -> ()
+    | C.HCFALSE
+    | C.HCVAR _ -> ()
     | C.HCAP name ->
         if C.isNominal name then begin
           Hashtbl.replace nomset name s;