diff --git a/etherlink/bin_node/lib_dev/observer.ml b/etherlink/bin_node/lib_dev/observer.ml
index 53a18eeb2509dde65bb5845eab7e07c117ca3b2f..2f037e7d123c3d3a3d241a98328ac5ebfa3fe7d0 100644
--- a/etherlink/bin_node/lib_dev/observer.ml
+++ b/etherlink/bin_node/lib_dev/observer.ml
@@ -72,7 +72,7 @@ end) : Services_backend_sig.Backend = struct
 end
 
 let on_new_blueprint (ctxt : Evm_context.t) (blueprint : Blueprint_types.t) =
-  let (Qty level) = ctxt.next_blueprint_number in
+  let (Qty level) = blueprint.number in
   let (Qty number) = ctxt.next_blueprint_number in
   if Z.(equal level number) then
     Evm_context.apply_blueprint ctxt blueprint.payload