diff --git a/app/components/dossiers/deleted_dossiers_component.rb b/app/components/dossiers/deleted_dossiers_component.rb
index ab1d2f9c5..4e99cc402 100644
--- a/app/components/dossiers/deleted_dossiers_component.rb
+++ b/app/components/dossiers/deleted_dossiers_component.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Dossiers::DeletedDossiersComponent < ApplicationComponent
   include DossierHelper
 
diff --git a/db/migrate/20240718100430_rename_supprimes_recemment_from_procedure_presentation.rb b/db/migrate/20240718100430_rename_supprimes_recemment_from_procedure_presentation.rb
index fb8a63ded..864f1fe57 100644
--- a/db/migrate/20240718100430_rename_supprimes_recemment_from_procedure_presentation.rb
+++ b/db/migrate/20240718100430_rename_supprimes_recemment_from_procedure_presentation.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class RenameSupprimesRecemmentFromProcedurePresentation < ActiveRecord::Migration[7.0]
   def up
     ProcedurePresentation.update_all(%Q(filters = filters || '{"supprimes": []}'))
diff --git a/spec/models/procedure_presentation_spec.rb b/spec/models/procedure_presentation_spec.rb
index 3403c1489..475719331 100644
--- a/spec/models/procedure_presentation_spec.rb
+++ b/spec/models/procedure_presentation_spec.rb
@@ -834,7 +834,7 @@ describe ProcedurePresentation do
       let(:procedure) { create(:procedure, types_de_champ_public: [{ type: :yes_no }]) }
 
       it 'should downcase and transform value' do
-        procedure_presentation.add_filter("suivis", "type_de_champ/#{first_type_de_champ_id}", "Oui")
+        procedure_presentation.add_filter("suivis", "type_de_champ/#{first_type_de_champ_id}", +"Oui")
 
         expect(procedure_presentation.filters).to eq({
           "suivis" =>
diff --git a/spec/models/siret_spec.rb b/spec/models/siret_spec.rb
index 5006e2583..0b67d28f9 100644
--- a/spec/models/siret_spec.rb
+++ b/spec/models/siret_spec.rb
@@ -1,7 +1,7 @@
 # frozen_string_literal: true
 
 describe Siret, type: :model do
-  subject { Siret.new(siret: siret) }
+  subject { Siret.new(siret: siret.dup) } # .dup in order to simulate a non literal user string
 
   context 'with no siret provided' do
     let(:siret) { '' }
diff --git a/spec/services/france_connect_service_spec.rb b/spec/services/france_connect_service_spec.rb
index 56349dbb4..c2cde5c5a 100644
--- a/spec/services/france_connect_service_spec.rb
+++ b/spec/services/france_connect_service_spec.rb
@@ -3,7 +3,7 @@
 describe FranceConnectService do
   describe '.retrieve_user_informations_particulier' do
     let(:code) { 'plop' }
-    let(:access_token) { 'my access_token' }
+    let(:access_token) { +'my access_token' }
 
     let(:given_name) { 'plop1' }
     let(:family_name) { 'plop2' }
diff --git a/spec/services/procedure_archive_service_spec.rb b/spec/services/procedure_archive_service_spec.rb
index 9e45db854..96f040324 100644
--- a/spec/services/procedure_archive_service_spec.rb
+++ b/spec/services/procedure_archive_service_spec.rb
@@ -112,7 +112,7 @@ describe ProcedureArchiveService do
             expect(zip_entries.map(&:filename)).to match_array(structure)
             zip_entries.map do |entry|
               next unless entry.filename == "#{service.send(:zip_root_folder, archive)}/-LISTE-DES-FICHIERS-EN-ERREURS.txt"
-              extracted_content = ""
+              extracted_content = +""
               extractor = entry.extractor_from(f)
               extracted_content << extractor.extract(1024 * 1024) until extractor.eof?
               expect(extracted_content).to match(/Impossible de .* .*cni.*png/)