diff --git a/tests/Template/TemplateTest.php b/tests/Template/TemplateTest.php
index d621bf0cb..9ab88612c 100644
--- a/tests/Template/TemplateTest.php
+++ b/tests/Template/TemplateTest.php
@@ -2018,7 +2018,7 @@ class TemplateTest extends TestCase
                     $templated_list->add(5, []);',
                 'error_message' => 'InvalidArgument',
             ],
-            'unionTemplateType' => [
+            'classTemplateUnionType' => [
                 '<?php
                     /**
                      * @template T0 as int|string
@@ -2026,6 +2026,14 @@ class TemplateTest extends TestCase
                     class Foo {}',
                 'error_message' => 'InvalidDocblock'
             ],
+            'functionTemplateUnionType' => [
+                '<?php
+                    /**
+                     * @template T0 as int|string
+                     */
+                    function foo() : void {}',
+                'error_message' => 'InvalidDocblock'
+            ],
         ];
     }
 }