diff --git a/tests/forms_tests/tests/test_forms.py b/tests/forms_tests/tests/test_forms.py
index 877571726d..7ea88f0cc8 100644
--- a/tests/forms_tests/tests/test_forms.py
+++ b/tests/forms_tests/tests/test_forms.py
@@ -3097,6 +3097,23 @@ Options: <select multiple name="options" aria-invalid="true" required>
             "</span></td></tr>",
         )
 
+    def test_aria_describedby_custom_widget_id(self):
+        class UserRegistration(Form):
+            username = CharField(
+                max_length=255,
+                help_text="e.g., user@example.com",
+                widget=TextInput(attrs={"id": "custom-id"}),
+            )
+
+        f = UserRegistration()
+        self.assertHTMLEqual(
+            str(f),
+            '<div><label for="custom-id">Username:</label>'
+            '<div class="helptext" id="id_username_helptext">e.g., user@example.com'
+            '</div><input type="text" name="username" id="custom-id" maxlength="255" '
+            'required aria-describedby="id_username_helptext"></div>',
+        )
+
     def test_as_widget_custom_aria_describedby(self):
         class FoodForm(Form):
             intl_name = CharField(help_text="The food's international name.")