diff --git a/src/TypedData/PatternDataDefinition.php b/src/TypedData/PatternDataDefinition.php
index a0e89b90204b5eced39471f53af9bf98b5d9f280..93f17892d40e35bbd1a7b9fdc88185694c5b86f0 100644
--- a/src/TypedData/PatternDataDefinition.php
+++ b/src/TypedData/PatternDataDefinition.php
@@ -42,7 +42,7 @@ class PatternDataDefinition extends MapDataDefinition {
       ->setPropertyDefinition('base path', DataDefinition::create('string')->setRequired(TRUE))
       ->setPropertyDefinition('file name', DataDefinition::create('string')->setRequired(TRUE))
       ->setPropertyDefinition('provider', DataDefinition::create('string')->setRequired(TRUE))
-      ->setPropertyDefinition('fields', $this->getFieldsDefinition()->setRequired(TRUE))
+      ->setPropertyDefinition('fields', $this->getFieldsDefinition())
       ->setPropertyDefinition('theme hook', DataDefinition::create('string')->setRequired(TRUE))
       ->setPropertyDefinition('description', DataDefinition::create('string'))
       ->setPropertyDefinition('use', DataDefinition::create('string'))
diff --git a/tests/features/overview.feature b/tests/features/overview.feature
index 3f5a74ac01eb45f8bca4c9f3cf1f20cc971f02b5..fd4354f3fac5251c9e99ca913a3da3a71f0c7a43 100644
--- a/tests/features/overview.feature
+++ b/tests/features/overview.feature
@@ -81,11 +81,9 @@ Feature: Overview
       | error messages                                                                 |
       | Pattern 'bad_pattern' is skipped because of the following validation error(s): |
       | Validation error on "bad_pattern.label": This value should not be null.        |
-      | Validation error on "bad_pattern.fields": This value should not be null.       |
 
     And I reload the page
     Then I should not see the following error messages:
       | error messages                                                                 |
       | Pattern 'bad_pattern' is skipped because of the following validation error(s): |
       | Validation error on "bad_pattern.label": This value should not be null.        |
-      | Validation error on "bad_pattern.fields": This value should not be null.       |
diff --git a/tests/src/fixtures/validation.yml b/tests/src/fixtures/validation.yml
index 4ae35e26d8ca9769d2fc95fd4e0533bcedfe0392..8507a14c47251869e11ec89ae29729f40fac6bb7 100644
--- a/tests/src/fixtures/validation.yml
+++ b/tests/src/fixtures/validation.yml
@@ -7,7 +7,6 @@
     - "base path: This value should not be null."
     - "file name: This value should not be null."
     - "provider: This value should not be null."
-    - "fields: This value should not be null."
     - "theme hook: This value should not be null."
 -
   pattern:
@@ -18,7 +17,6 @@
     - "base path: This value should not be null."
     - "file name: This value should not be null."
     - "provider: This value should not be null."
-    - "fields: This value should not be null."
     - "theme hook: This value should not be null."
 -
   pattern:
@@ -26,12 +24,14 @@
     label: label
     description: description
     fields:
-      not valid name:
+      fass:
+        name: 'not valid name'
   messages:
     - "base path: This value should not be null."
     - "file name: This value should not be null."
     - "provider: This value should not be null."
-    - "fields: This value should not be null."
+    - "fields.0.name: This value is not valid."
+    - "fields.0.label: This value should not be null."
     - "theme hook: This value should not be null."
 -
   pattern: