diff --git a/src/main.rs b/src/main.rs
index 208b010..cb70b49 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -110,7 +110,8 @@ impl Robot {
         }
     }
     /// Apply right instruction to the robot.
-    fn move_right(&mut self) {
+    fn move_right(&mut self, w: &mut World) {
+        w.map[(self.p.x + (self.p.y * w.x as i32)) as usize] = '.';
         match self.o {
             Orientation::N => self.p.x += 1,
             Orientation::S => self.p.x -= 1,
@@ -119,7 +120,8 @@ impl Robot {
         }
     }
     /// Apply left instruction to the robot.
-    fn move_left(&mut self) {
+    fn move_left(&mut self, w: &mut World) {
+        w.map[(self.p.x + (self.p.y * w.x as i32)) as usize] = '.';
         match self.o {
             Orientation::N => self.p.x -= 1,
             Orientation::S => self.p.x += 1,
@@ -307,9 +309,9 @@ mod tests {
         w.create();
         r.move_forward(&mut w);
         assert_eq!(0, r.p.y);
-        r.move_right();
+        r.move_right(&mut w);
         assert_eq!(2, r.p.x);
-        r.move_left();
+        r.move_left(&mut w);
         assert_eq!(1, r.p.x);
     }