1 files changed, 2 insertions, 0 deletions
diff --git a/drawing.c b/drawing.c
index 7f4a6cf..a10a7f0 100644
--- a/drawing.c
+++ b/drawing.c
@@ -90,6 +90,8 @@ void draw_line(drawing *dr, int x1, int y1, int x2, int y2, int colour)
 void draw_thick_line(drawing *dr, float thickness,
 		     float x1, float y1, float x2, float y2, int colour)
 {
+    if (thickness < 1.0)
+        thickness = 1.0;
     if (dr->api->draw_thick_line) {
 	dr->api->draw_thick_line(dr->handle, thickness,
 				 x1, y1, x2, y2, colour);