diff --git a/htdocs/css/admin.css b/htdocs/css/admin.css
index 7597188..0369d72 100644
--- a/htdocs/css/admin.css
+++ b/htdocs/css/admin.css
@@ -117,17 +117,17 @@ table.bookmarks .frequency {
     overflow-y: auto;
 }
 
-.removable-group.removable {
+.removable-group.removable, .add-group {
     display: flex;
     flex-direction: row;
 }
 
-.removable-group.removable .removable-item {
+.removable-group.removable .removable-item, .add-group .add-group-select {
     flex: 1 0 auto;
     margin-right: .25rem;
 }
 
-.removable-group.removable .option-remove-button {
+.removable-group.removable .option-remove-button, .add-group .option-add-button {
     flex: 0 0 70px;
 }
 
diff --git a/owrx/source/__init__.py b/owrx/source/__init__.py
index e752f09..706b576 100644
--- a/owrx/source/__init__.py
+++ b/owrx/source/__init__.py
@@ -410,13 +410,13 @@ class OptionalSection(Section):
                 <label class="col-form-label col-form-label-sm col-3">
                     Additional optional settings
                 </label>
-                <div class="input-group input-group-sm col-9 p-0">
-                    <select class="form-control from-control-sm optional-select">
-                        {options}
-                    </select>
-                    <div class="input-group-append">
-                        <button type="button" class="btn btn-success option-add-button">Add</button>
+                <div class="add-group col-9 p-0">
+                    <div class="add-group-select">
+                        <select class="form-control form-control-sm optional-select">
+                            {options}
+                        </select>
                     </div>
+                    <button type="button" class="btn btn-sm btn-success option-add-button">Add</button>
                 </div>
             </div>
         """.format(