diff --git a/kitty/fonts.c b/kitty/fonts.c
index 6942c9f48..765b1f96c 100644
--- a/kitty/fonts.c
+++ b/kitty/fonts.c
@@ -203,7 +203,7 @@ font_group_for(double font_sz_in_pts, double logical_dpi_x, double logical_dpi_y
 
 static inline void
 clear_canvas(FontGroup *fg) {
-    if (fg->canvas.buf) memset(fg->canvas.buf, 0, sizeof(pixel) * fg->canvas.current_cells * 3u * fg->cell_width * fg->cell_height);
+    if (fg->canvas.buf) memset(fg->canvas.buf, 0, sizeof(fg->canvas.buf[0]) * fg->canvas.current_cells * 3u * fg->cell_width * fg->cell_height);
 }
 
 
@@ -633,7 +633,7 @@ static inline pixel*
 extract_cell_from_canvas(FontGroup *fg, unsigned int i, unsigned int num_cells) {
     pixel *ans = fg->canvas.buf + (fg->cell_width * fg->cell_height * (fg->canvas.current_cells - 1)), *dest = ans, *src = fg->canvas.buf + (i * fg->cell_width);
     unsigned int stride = fg->cell_width * num_cells;
-    for (unsigned int r = 0; r < fg->cell_height; r++, dest += fg->cell_width, src += stride) memcpy(dest, src, fg->cell_width * sizeof(pixel));
+    for (unsigned int r = 0; r < fg->cell_height; r++, dest += fg->cell_width, src += stride) memcpy(dest, src, fg->cell_width * sizeof(fg->canvas.buf[0]));
     return ans;
 }