diff --git a/src/shape.rs b/src/shape.rs
index ff654b1..9216592 100644
--- a/src/shape.rs
+++ b/src/shape.rs
@@ -1616,7 +1616,7 @@ impl ShapeLine {
                                 _ => font_size,
                             };
 
-                            let x_advance = glyph_font_size.mul_add(
+                            let mut x_advance = glyph_font_size.mul_add(
                                 glyph.x_advance,
                                 if word.blank {
                                     justification_expansion
@@ -1624,6 +1624,10 @@ impl ShapeLine {
                                     0.0
                                 },
                             );
+                            if let Some(match_em_width) = match_mono_em_width {
+                                // Round to nearest monospace width
+                                x_advance = ((x_advance / match_em_width).round()) * match_em_width;
+                            }
                             if self.rtl {
                                 x -= x_advance;
                             }