diff --git a/src/Entity/Pattern.php b/src/Entity/Pattern.php
index af7b15e..2852c10 100644
--- a/src/Entity/Pattern.php
+++ b/src/Entity/Pattern.php
@@ -164,7 +164,7 @@ public function getAssets() {
   }
 
   public function getCategory() {
-    return $this->getEntityKey('category');
+    return $this->getEntityKey('category') ?? t('default');
   }
 
   public function getDescription() {
diff --git a/src/PatternLibraryPluginDefinition.php b/src/PatternLibraryPluginDefinition.php
index 84a8fc1..7e3272a 100644
--- a/src/PatternLibraryPluginDefinition.php
+++ b/src/PatternLibraryPluginDefinition.php
@@ -153,7 +153,7 @@ public function setDescription($description) {
    *   The human-readable category of the definition.
    */
   public function getCategory() {
-    return $this->category;
+    return $this->category ?? t('default');
   }
 
   /**
@@ -165,7 +165,7 @@ public function getCategory() {
    * @return $this
    */
   public function setCategory($category) {
-    $this->category = $category;
+    $this->category = $category ?? t('default');
     return $this;
   }
 
diff --git a/src/Plugin/Derivative/PatternkitBlock.php b/src/Plugin/Derivative/PatternkitBlock.php
index 81c9865..1846e25 100644
--- a/src/Plugin/Derivative/PatternkitBlock.php
+++ b/src/Plugin/Derivative/PatternkitBlock.php
@@ -149,7 +149,7 @@ public function getDerivativeDefinitions($base_definition): array {
       $this->derivatives[$pattern_id] = [
         'category' => (string) t('Patternkit:@lib/@category', [
           '@lib'      => $lib ?? 'patternkit',
-          '@category' => $pattern->getCategory() ?? 'default',
+          '@category' => $pattern->getCategory() ?? t('default'),
         ]),
         'admin_label' => t('[Patternkit] @pattern', ['@pattern' => $pattern->label()]),
         'pattern' => $pattern,