diff --git a/CHANGELOG.md b/CHANGELOG.md
index 2e14edf0..c27eb646 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -75,8 +75,10 @@
 
 
 ### Deprecated
+
 * **bell** option in `foot.ini`; set actions in **[bell]** section instead.
 
+
 ### Removed
 
 * Buffer damage quirk for Plasma/KWin.
@@ -93,6 +95,9 @@
   (https://codeberg.org/dnkl/foot/issues/495).
 * Assertion when emitting a sixel occupying the entire scrollback
   history (https://codeberg.org/dnkl/foot/issues/494).
+* Font underlines being positioned below the cell (and thus being
+  invisible) for certain combinations of fonts and font sizes
+  (https://codeberg.org/dnkl/foot/issues/503).
 
 
 ### Security
diff --git a/render.c b/render.c
index 1454c84a..8481d330 100644
--- a/render.c
+++ b/render.c
@@ -317,11 +317,14 @@ draw_underline(const struct terminal *term, pixman_image_t *pix,
                const struct fcft_font *font,
                const pixman_color_t *color, int x, int y, int cols)
 {
+    /* Make sure the line isn't positioned below the cell */
+    int y_ofs = font_baseline(term) - font->underline.position;
+    y_ofs = min(y_ofs, term->cell_height - font->underline.thickness);
+
     pixman_image_fill_rectangles(
         PIXMAN_OP_SRC, pix, color,
         1, &(pixman_rectangle16_t){
-            x, y + font_baseline(term) - font->underline.position,
-            cols * term->cell_width, font->underline.thickness});
+            x, y + y_ofs, cols * term->cell_width, font->underline.thickness});
 }
 
 static void