diff --git a/src/Plugin/search_api/processor/Grouping.php b/src/Plugin/search_api/processor/Grouping.php
index e0db713..48f8139 100755
--- a/src/Plugin/search_api/processor/Grouping.php
+++ b/src/Plugin/search_api/processor/Grouping.php
@@ -89,11 +89,11 @@ class Grouping extends FieldsProcessorPluginBase implements PluginFormInterface
     ];
 
     $form['group_limit'] = [
-      '#type' => 'textfield',
+      '#type' => 'number',
       '#title' => $this->t('Results per group'),
       '#description' => $this->t('The number of results are limited per group. By default, 1 result per group is returned.'),
       '#default_value' => $this->configuration['group_limit'],
-      '#element_validate' => ['element_validate_integer_positive'],
+      '#min' => 1,
       '#size' => 3,
     ];