diff --git a/dm5/lib/lib.ml b/dm5/lib/lib.ml
index 68058fd..ab23ff6 100644
--- a/dm5/lib/lib.ml
+++ b/dm5/lib/lib.ml
@@ -42,7 +42,8 @@ let bitonique t =
         grows := false)
     else
       if t.(!i) < t.(!i+1) then
-        res := false
+        res := false;
+    i := !i + 1
   done;
   !res
 ;;