diff --git a/src/lib/CoAlgLogics.ml b/src/lib/CoAlgLogics.ml
index 2a738c5678a858b272bca174ee0842739c60b430..c151b7f264913a21dd0651c12c1698003f51bb85 100644
--- a/src/lib/CoAlgLogics.ml
+++ b/src/lib/CoAlgLogics.ml
@@ -66,7 +66,7 @@ let mkRuleList_MultiModalK sort bs defer sl : rule list =
           (* if f1 = ∀R.D then bs1 = bs1 ∪ { D } *)
           let nextf1 = (lfGetDest1 sort f1) in
           bsetAdd bs1 nextf1;
-          (if (bsetMem defer f1) &&
+          (if (bsetMem deferral f1) &&
                 (lfGetDeferral sort f1) = (lfGetDeferral sort nextf1) then
              bsetAdd defer1 nextf1;)
         else ()