diff --git a/generator/filter_collection.cpp b/generator/filter_collection.cpp
index 1d67f6ec3a..6164077b82 100644
--- a/generator/filter_collection.cpp
+++ b/generator/filter_collection.cpp
@@ -13,7 +13,7 @@ std::shared_ptr<FilterInterface> FilterCollection::Clone() const
 {
   auto p = std::make_shared<FilterCollection>();
   for (auto const & c : m_collection)
-   p->Append(c->Clone());
+    p->Append(c->Clone());
   return p;
 }