diff --git a/Userland/Libraries/LibWeb/Layout/FlexFormattingContext.cpp b/Userland/Libraries/LibWeb/Layout/FlexFormattingContext.cpp
index 5609a79cc3..9bece55642 100644
--- a/Userland/Libraries/LibWeb/Layout/FlexFormattingContext.cpp
+++ b/Userland/Libraries/LibWeb/Layout/FlexFormattingContext.cpp
@@ -867,7 +867,7 @@ void FlexFormattingContext::collect_flex_items_into_flex_lines()
     CSSPixels line_main_size = 0;
     for (auto& flex_item : m_flex_items) {
         auto outer_hypothetical_main_size = flex_item.hypothetical_main_size + flex_item.margins.main_before + flex_item.margins.main_after + flex_item.borders.main_before + flex_item.borders.main_after + flex_item.padding.main_before + flex_item.padding.main_after;
-        if (!line.items.is_empty() && (line_main_size + outer_hypothetical_main_size) > specified_main_size(flex_container())) {
+        if (!line.items.is_empty() && (line_main_size + outer_hypothetical_main_size) > m_available_space_for_items->main.to_px_or_zero()) {
             m_flex_lines.append(move(line));
             line = {};
             line_main_size = 0;
@@ -895,7 +895,7 @@ void FlexFormattingContext::resolve_flexible_lengths()
         for (auto& flex_item : flex_line.items) {
             sum_of_hypothetical_main_sizes += (flex_item->hypothetical_main_size + flex_item->margins.main_before + flex_item->margins.main_after + flex_item->borders.main_before + flex_item->borders.main_after + flex_item->padding.main_before + flex_item->padding.main_after);
         }
-        if (sum_of_hypothetical_main_sizes < specified_main_size(flex_container()))
+        if (sum_of_hypothetical_main_sizes < m_available_space_for_items->main.to_px_or_zero())
             used_flex_factor = FlexFactor::FlexGrowFactor;
         else
             used_flex_factor = FlexFactor::FlexShrinkFactor;
@@ -937,7 +937,7 @@ void FlexFormattingContext::resolve_flexible_lengths()
                 else
                     sum_of_items_on_line += flex_item->flex_base_size + flex_item->margins.main_before + flex_item->margins.main_after + flex_item->borders.main_before + flex_item->borders.main_after + flex_item->padding.main_before + flex_item->padding.main_after;
             }
-            return specified_main_size(flex_container()) - sum_of_items_on_line;
+            return m_available_space_for_items->main.to_px_or_zero() - sum_of_items_on_line;
         };
 
         CSSPixels initial_free_space = calculate_free_space();