diff --git a/Tests/LibWeb/Layout/expected/block-and-inline/percentage-padding-on-inline-block-with-indefinite-containing-block-size.txt b/Tests/LibWeb/Layout/expected/block-and-inline/percentage-padding-on-inline-block-with-indefinite-containing-block-size.txt
new file mode 100644
index 0000000000..13f311acaf
--- /dev/null
+++ b/Tests/LibWeb/Layout/expected/block-and-inline/percentage-padding-on-inline-block-with-indefinite-containing-block-size.txt
@@ -0,0 +1,6 @@
+Viewport <#document> at (0,0) content-size 800x600 children: not-inline
+ BlockContainer at (0,0) content-size 800x33.46875 [BFC] children: not-inline
+ BlockContainer
at (8,8) content-size 0x17.46875 children: inline
+ line 0 width: 0, height: 17.46875, bottom: 17.46875, baseline: 13.53125
+ frag 0 from BlockContainer start: 0, length: 0, rect: [8,21 0x0]
+ BlockContainer at (8,21) content-size 0x0 inline-block [BFC] children: not-inline
diff --git a/Tests/LibWeb/Layout/input/block-and-inline/percentage-padding-on-inline-block-with-indefinite-containing-block-size.html b/Tests/LibWeb/Layout/input/block-and-inline/percentage-padding-on-inline-block-with-indefinite-containing-block-size.html
new file mode 100644
index 0000000000..3a03a9ad07
--- /dev/null
+++ b/Tests/LibWeb/Layout/input/block-and-inline/percentage-padding-on-inline-block-with-indefinite-containing-block-size.html
@@ -0,0 +1,9 @@
+
\ No newline at end of file
diff --git a/Userland/Libraries/LibWeb/Layout/InlineFormattingContext.cpp b/Userland/Libraries/LibWeb/Layout/InlineFormattingContext.cpp
index 24b585d31a..4ae23ea0f4 100644
--- a/Userland/Libraries/LibWeb/Layout/InlineFormattingContext.cpp
+++ b/Userland/Libraries/LibWeb/Layout/InlineFormattingContext.cpp
@@ -89,7 +89,7 @@ void InlineFormattingContext::run(Box const&, LayoutMode layout_mode, AvailableS
void InlineFormattingContext::dimension_box_on_line(Box const& box, LayoutMode layout_mode)
{
- auto width_of_containing_block = m_available_space->width.to_px();
+ auto width_of_containing_block = m_available_space->width.to_px_or_zero();
auto& box_state = m_state.get_mutable(box);
auto const& computed_values = box.computed_values();