diff --git a/src/lib/CoAlgLogics.ml b/src/lib/CoAlgLogics.ml
index 45d99f410094db6382f78851512fb86b9685003a..2a738c5678a858b272bca174ee0842739c60b430 100644
--- a/src/lib/CoAlgLogics.ml
+++ b/src/lib/CoAlgLogics.ml
@@ -135,7 +135,13 @@ let mkRule_MultiModalKD sort bs defer sl : stateExpander =
     let f formula =
       if lfGetType sort formula = AxF
          && lfGetDest3 sort formula = r
-      then ignore (bsetAdd succs (lfGetDest1 sort formula))
+      then
+          let nextf1 = (lfGetDest1 sort formula) in
+          bsetAdd succs nextf1;
+          ignore (if (bsetMem defer formula) &&
+                       (lfGetDeferral sort formula) = (lfGetDeferral sort nextf1)
+                  then
+                    bsetAdd defer1 nextf1;)
       else ()
     in
     bsetIter f bs;