diff --git a/Userland/Libraries/LibWeb/DOM/Document.cpp b/Userland/Libraries/LibWeb/DOM/Document.cpp
index 0369b42a3c..fc49ffa2e0 100644
--- a/Userland/Libraries/LibWeb/DOM/Document.cpp
+++ b/Userland/Libraries/LibWeb/DOM/Document.cpp
@@ -405,6 +405,8 @@ void Document::update_layout()
     if (!browsing_context())
         return;
 
+    auto viewport_rect = browsing_context()->viewport_rect();
+
     update_style();
 
     if (!m_layout_root) {
@@ -413,6 +415,9 @@ void Document::update_layout()
     }
 
     Layout::BlockFormattingContext root_formatting_context(*m_layout_root, nullptr);
+    m_layout_root->build_stacking_context_tree();
+    m_layout_root->set_content_size(viewport_rect.size().to_type<float>());
+
     root_formatting_context.run(*m_layout_root, Layout::LayoutMode::Default);
 
     m_layout_root->set_needs_display();
diff --git a/Userland/Libraries/LibWeb/Layout/BlockFormattingContext.cpp b/Userland/Libraries/LibWeb/Layout/BlockFormattingContext.cpp
index fb7f8c4275..edf3427e88 100644
--- a/Userland/Libraries/LibWeb/Layout/BlockFormattingContext.cpp
+++ b/Userland/Libraries/LibWeb/Layout/BlockFormattingContext.cpp
@@ -532,10 +532,6 @@ void BlockFormattingContext::layout_initial_containing_block(LayoutMode layout_m
     auto viewport_rect = root().browsing_context().viewport_rect();
 
     auto& icb = verify_cast<Layout::InitialContainingBlock>(root());
-    icb.build_stacking_context_tree();
-
-    icb.set_content_width(viewport_rect.width());
-    icb.set_content_height(viewport_rect.height());
 
     VERIFY(!icb.children_are_inline());
     layout_block_level_children(root(), layout_mode);