diff --git a/src/Config/Definition/DynamicArrayNode.php b/src/Config/Definition/DynamicArrayNode.php
index b601aee..85d9c00 100644
--- a/src/Config/Definition/DynamicArrayNode.php
+++ b/src/Config/Definition/DynamicArrayNode.php
@@ -55,8 +55,11 @@ protected function mergeValues($leftSide, $rightSide)
             }
 
             if (!isset($this->children[$k])) {
-                $this->children[$k] = new DynamicArrayNode($k);
+                $node = new DynamicArrayNode($k);
+                $node->setIgnoreExtraKeys($this->ignoreExtraKeys, $this->removeExtraKeys);
+                $this->children[$k] = $node;
             }
+
             $leftSide[$k] = $this->children[$k]->merge($leftSide[$k], $v);
         }