diff --git a/Tests/LibWeb/Layout/expected/ifc-float-left-and-sibling-with-margin-left.txt b/Tests/LibWeb/Layout/expected/ifc-float-left-and-sibling-with-margin-left.txt
new file mode 100644
index 0000000000..efc8ed23b4
--- /dev/null
+++ b/Tests/LibWeb/Layout/expected/ifc-float-left-and-sibling-with-margin-left.txt
@@ -0,0 +1,9 @@
+Viewport <#document> at (0,0) content-size 800x600 children: not-inline
+ BlockContainer at (1,1) content-size 798x61 children: not-inline
+ BlockContainer
at (10,10) content-size 780x19.46875 children: not-inline
+ BlockContainer at (11,11) content-size 50x50 floating children: not-inline
+ BlockContainer at (91,11) content-size 698x17.46875 children: inline
+ line 0 width: 125.125, height: 17.46875, bottom: 17.46875, baseline: 13.53125
+ frag 0 from TextNode start: 0, length: 14, rect: [91,11 125.125x17.46875]
+ "Chrono Trigger"
+ TextNode <#text>
diff --git a/Tests/LibWeb/Layout/input/ifc-float-left-and-sibling-with-margin-left.html b/Tests/LibWeb/Layout/input/ifc-float-left-and-sibling-with-margin-left.html
new file mode 100644
index 0000000000..d44e5f5ce4
--- /dev/null
+++ b/Tests/LibWeb/Layout/input/ifc-float-left-and-sibling-with-margin-left.html
@@ -0,0 +1,16 @@
+Chrono Trigger
\ No newline at end of file
diff --git a/Userland/Libraries/LibWeb/Layout/LineBuilder.cpp b/Userland/Libraries/LibWeb/Layout/LineBuilder.cpp
index 572fa0dba0..89b735d208 100644
--- a/Userland/Libraries/LibWeb/Layout/LineBuilder.cpp
+++ b/Userland/Libraries/LibWeb/Layout/LineBuilder.cpp
@@ -158,6 +158,10 @@ void LineBuilder::update_last_line()
CSSPixels x_offset_bottom = m_context.leftmost_x_offset_at(m_current_y + current_line_height - 1);
CSSPixels x_offset = max(x_offset_top, x_offset_bottom);
+ // If the IFC's containing block has left-side margin, it has already been shifted to the right by that amount.
+ // We subtract the margin-left here to ensure that the left-side "space used by floats" doesn't get applied twice.
+ x_offset = max(CSSPixels(0), x_offset - m_containing_block_state.margin_left);
+
CSSPixels excess_horizontal_space = m_available_width_for_current_line - line_box.width();
switch (text_align) {