diff --git a/app/models/groupe_instructeur.rb b/app/models/groupe_instructeur.rb
index f7ecf059d..524d9e9c8 100644
--- a/app/models/groupe_instructeur.rb
+++ b/app/models/groupe_instructeur.rb
@@ -92,7 +92,7 @@ class GroupeInstructeur < ApplicationRecord
   end
 
   def valid_rule_line?(rule)
-    ([rule.left, rule, rule.right] in [ChampValue, (LessThan | LessThanEq | Eq | NotEq | GreaterThanEq | GreaterThan | IncludeOperator | ExcludeOperator), Constant]) && routing_rule_matches_tdc?(rule)
+    !rule.is_a?(EmptyOperator) && routing_rule_matches_tdc?(rule)
   end
 
   def non_unique_rule?
diff --git a/spec/models/routing_engine_spec.rb b/spec/models/routing_engine_spec.rb
index 36ea5bc63..4692638d7 100644
--- a/spec/models/routing_engine_spec.rb
+++ b/spec/models/routing_engine_spec.rb
@@ -28,7 +28,7 @@ describe RoutingEngine, type: :model do
       context 'without any matching rules' do
         before do
           procedure.groupe_instructeurs.each do |gi|
-            gi.update(routing_rule: ds_eq(constant(false), constant(false)))
+            gi.update(routing_rule: ds_eq(constant(false), constant(true)))
           end
         end