diff --git a/backend/CSE3analysisaux.ml b/backend/CSE3analysisaux.ml
index 6e190d35023ebf56011e36b23d8bf6b0e35e0221..bd4ca20afcacd33c090e03cd17e2d9b529117b7c 100644
--- a/backend/CSE3analysisaux.ml
+++ b/backend/CSE3analysisaux.ml
@@ -125,7 +125,8 @@ let refine_invariants
   let add_todo (pc : RTL.node) =
     todo := IntSet.add (P.to_int pc) !todo in 
   let update_node (pc : RTL.node) =
-    Printf.printf "updating node %d\n" (P.to_int pc);
+    (if !Clflags.option_debug_compcert > 9
+     then Printf.printf "updating node %d\n" (P.to_int pc));
     if not (peq pc entrypoint)
     then
       let cur = PMap.get pc !invariants in