diff --git a/datamodels/2.x/itop-core-update/view/ConfirmUpdate.html.twig b/datamodels/2.x/itop-core-update/view/ConfirmUpdate.html.twig
index af7cfd7a7..b8d37189e 100644
--- a/datamodels/2.x/itop-core-update/view/ConfirmUpdate.html.twig
+++ b/datamodels/2.x/itop-core-update/view/ConfirmUpdate.html.twig
@@ -30,10 +30,10 @@
         {% UIFieldSet Standard {'sLegend':'iTopUpdate:UI:Action'|dict_s} %}
             {% UIAlert ForWarning {'sContent':'iTopUpdate:UI:WarningReadOnlyDuringUpdate'|dict_s} %}{% EndUIAlert %}
             {# <div> #}
-            {% UIForm Standard {'CSSClasses':'form-inline'} %}
+            {% UIForm Standard {'CSSClasses':['form-inline']} %}
                 {% UIButton ForSecondaryAction {'sId':'cancel-update', 'sLabel':'iTopUpdate:UI:Cancel'|dict_s, 'bIsSubmit':true} %}
             {% EndUIForm %}
-            {% UIForm Standard {'CSSClasses':'form-inline'} %}
+            {% UIForm Standard {'CSSClasses':['form-inline']} %}
                 {% UIButton ForPrimaryAction {'sId':'do-update', 'sLabel':'iTopUpdate:UI:DoUpdate'|dict_s, 'bIsSubmit':true} %}
                 {% UISpinner Standard {'sId':'submit-wait', 'IsHidden':true} %}
                 {% UIInput ForHidden {'sName':'operation', 'sValue':'UpdateCoreFiles'} %}
diff --git a/datamodels/2.x/itop-core-update/view/UpdateCoreFiles.html.twig b/datamodels/2.x/itop-core-update/view/UpdateCoreFiles.html.twig
index b49498004..956061bb0 100644
--- a/datamodels/2.x/itop-core-update/view/UpdateCoreFiles.html.twig
+++ b/datamodels/2.x/itop-core-update/view/UpdateCoreFiles.html.twig
@@ -53,7 +53,7 @@
             {% EndUIAlert %}
 
             {% UIContentBlock Standard {'sId':'run_setup','aContainerClasses':['ibo-update-core--run-setup'], 'IsHidden':true} %}
-                {% UIForm Standard {'CSSClasses':'form-inline'} %}
+                {% UIForm Standard {'CSSClasses':['form-inline']} %}
                     {% UIInput ForHidden {'sName':'operation', 'sValue':'RunSetup'} %}
                     {% UIInput ForHidden {'sName':'authent', 'sValue':sSetupToken} %}
                     {% UIInput ForHidden {'sName':'', 'sValue':''} %}
@@ -61,7 +61,7 @@
                 {% EndUIForm %}
             {% EndUIContentBlock %}
 
-            {% UIForm Standard {'CSSClasses':'form-inline'} %}
+            {% UIForm Standard {'CSSClasses':['form-inline']} %}
                 {% UIButton ForPrimaryAction {'sLabel':'iTopUpdate:UI:Continue'|dict_s, 'sId':'setup_continue', 'bIsSubmit':true, 'IsDisabled':false} %}
             {% EndUIForm %}