diff --git a/app/models/concerns/tags_substitution_concern.rb b/app/models/concerns/tags_substitution_concern.rb
index 0ba9b9bb5..d1d4df5df 100644
--- a/app/models/concerns/tags_substitution_concern.rb
+++ b/app/models/concerns/tags_substitution_concern.rb
@@ -19,6 +19,7 @@ module TagsSubstitutionConcern
         .sub(/[[:space:]]+$/, '')
         .gsub(/[[:space:]]/, ' ')
         .gsub(' ', ' ')
+        .gsub(/--/, '__')
     end
 
     define_combinator :doc do
diff --git a/spec/models/concern/tags_substitution_concern_spec.rb b/spec/models/concern/tags_substitution_concern_spec.rb
index 842429b79..e50ecfd70 100644
--- a/spec/models/concern/tags_substitution_concern_spec.rb
+++ b/spec/models/concern/tags_substitution_concern_spec.rb
@@ -203,6 +203,28 @@ describe TagsSubstitutionConcern, type: :model do
       end
     end
 
+    context 'when the procedure has a type de champ with double dash (--)' do
+      let(:types_de_champ_public) do
+        [
+          { libelle: "bon pote -- c'est top" }
+        ]
+      end
+
+      context 'and they are used in the template' do
+        let(:template) { "--bon pote __ c'est top--" }
+
+        context 'and their value in the dossier are not nil' do
+          before do
+            dossier.champs_public
+              .find { |champ| champ.libelle == "bon pote -- c'est top" }
+              .update(value: 'ceci est mon évènement')
+          end
+
+          it { is_expected.to eq('ceci est mon évènement') }
+        end
+      end
+    end
+
     context 'when the procedure has a type de champ repetition' do
       let(:template) { '--Répétition--' }
       let(:types_de_champ_public) { [{ type: :repetition, libelle: 'Répétition', mandatory: true, children: [{ libelle: 'Nom' }, { libelle: 'Prénom' }] }] }