diff --git a/app/components/polaris/dropzone_component.html.erb b/app/components/polaris/dropzone_component.html.erb
index 193f2053..6f03ca6d 100644
--- a/app/components/polaris/dropzone_component.html.erb
+++ b/app/components/polaris/dropzone_component.html.erb
@@ -87,12 +87,12 @@
     <template data-polaris-dropzone-target="previewTemplate">
       <%= tag.div(
         data: { polaris_dropzone_target: "preview" },
-        class: [
-          "Polaris-DropZone__Preview",
+        class: {
+          "Polaris-DropZone__Preview": true,
           "Polaris-DropZone__Preview--singleFile": !@multiple,
           "Polaris-DropZone__Preview--sizeMedium": @size == :medium,
           "Polaris-DropZone__Preview--sizeSmall": @size == :small,
-        ]
+        }
       ) do %>
         <% if @size.in?(%i[small]) %>
           <span class="target"></span>
diff --git a/test/components/polaris/dropzone_component_test.rb b/test/components/polaris/dropzone_component_test.rb
index f0ca17a2..11b1e6c6 100644
--- a/test/components/polaris/dropzone_component_test.rb
+++ b/test/components/polaris/dropzone_component_test.rb
@@ -15,6 +15,14 @@ def test_default_dropzone
     end
   end
 
+  def test_dropzone_preview_template
+    rendered = render_inline(Polaris::DropzoneComponent.new(name: :file_input))
+    template = rendered.at_css("template[data-polaris-dropzone-target=previewTemplate] > *").to_html
+    template_page = Capybara::Node::Simple.new(template)
+
+    assert_selector template_page, ".Polaris-DropZone__Preview", visible: :all
+  end
+
   def test_dropzone_with_label
     render_inline(Polaris::DropzoneComponent.new(label: "Dropzone Label", label_hidden: false))