diff --git a/lib/simple_form/components/labels.rb b/lib/simple_form/components/labels.rb
index 2cf4f781..3349554b 100644
--- a/lib/simple_form/components/labels.rb
+++ b/lib/simple_form/components/labels.rb
@@ -38,7 +38,7 @@ module SimpleForm
       end
 
       def label_html_options
-        label_options = html_options_for(:label, [input_type, required_class, SimpleForm.label_class])
+        label_options = html_options_for(:label, [input_type, required_class, SimpleForm.label_class].compact)
         label_options[:for] = options[:input_html][:id] if options.key?(:input_html) && options[:input_html].key?(:id)
         label_options
       end
diff --git a/test/components/label_test.rb b/test/components/label_test.rb
index 7cef72f1..87fecf5b 100644
--- a/test/components/label_test.rb
+++ b/test/components/label_test.rb
@@ -296,4 +296,13 @@ class IsolatedLabelTest < ActionView::TestCase
       assert_select 'label.my_custom_class'
     end
   end
+
+  test 'label strips extra classes even when label_class is nil' do
+    swap SimpleForm, :label_class => nil do
+      with_label_for @user, :name, :string
+      assert_select "label[class='string required']"
+      assert_no_select "label[class='string required ']"
+      assert_no_select "label[class=' string required']"
+    end
+  end
 end