diff --git a/src/CSSList/CSSBlockList.php b/src/CSSList/CSSBlockList.php
index 10a7778c..5ab91327 100644
--- a/src/CSSList/CSSBlockList.php
+++ b/src/CSSList/CSSBlockList.php
@@ -33,7 +33,7 @@ public function getAllDeclarationBlocks(): array
             if ($item instanceof DeclarationBlock) {
                 $result[] = $item;
             } elseif ($item instanceof CSSBlockList) {
-                $result = \array_merge($result, $item->getAllDeclarationBlocks());
+                \array_push($result, ...$item->getAllDeclarationBlocks());
             }
         }