1 files changed, 2 insertions, 0 deletions
diff --git a/lines.c b/lines.c
index d43c7fe..4ac624a 100644
--- a/lines.c
+++ b/lines.c
@@ -50,6 +50,8 @@ draw_vertical_line(RASTER *restrict raster, double x1, double y1, double y2, int
 
 	start = (size_t)y1;
 	end = (size_t)y2;
+	start -= (size_t)(start == raster->height);
+	end -= (size_t)(end == raster->height);
 
 	y = start;
 	if (ydir > 0) {