diff --git a/u02/src/sweep_line_tool.cpp b/u02/src/sweep_line_tool.cpp
index f132275..f098ad1 100644
--- a/u02/src/sweep_line_tool.cpp
+++ b/u02/src/sweep_line_tool.cpp
@@ -41,7 +41,7 @@ void sweep_line_tool::draw_interval(int b1, int b2, int y) {
 
 void sweep_line_tool::draw() { draw(10, 10, 90, 30, 30, 90); }
 
-void sweep_line_tool::draw(int _x, int _y) { draw(); }
+void sweep_line_tool::draw(int, int) { draw(); }
 
 void sweep_line_tool::draw(int x0, int y0, int x1, int y1, int x2, int y2) {
   /*