diff --git a/core/lib/Drupal/Core/Config/TypedConfigManager.php b/core/lib/Drupal/Core/Config/TypedConfigManager.php
index cad220c..155246d 100644
--- a/core/lib/Drupal/Core/Config/TypedConfigManager.php
+++ b/core/lib/Drupal/Core/Config/TypedConfigManager.php
@@ -170,16 +170,14 @@ protected function getDefinitionWithReplacements($base_plugin_id, array $replace
 
       // Replace dynamic portions of the definition type.
       if (!empty($replacements) && strpos($definition['type'], ']')) {
-        $sub_type = $this->determineType($this->replaceName($definition['type'], $replacements), $definitions);
+        $type = $this->determineType($this->replaceName($definition['type'], $replacements), $definitions);
         // Merge the newly determined subtype definition with the original
         // definition.
-        $definition = NestedArray::mergeDeepArray([$definitions[$sub_type], $definition], TRUE);
-      }
-      else {
-        // Unset type so we try the merge only once per type.
-        unset($definition['type']);
-        $this->definitions[$type] = $definition;
+        $definition = NestedArray::mergeDeepArray([$definitions[$type], $definition], TRUE);
       }
+      // Unset type so we try the merge only once per type.
+      unset($definition['type']);
+      $this->definitions[$type] = $definition;
     }
     // Add type and default definition class.
     $definition += array(