diff --git a/lib/entity.rb b/lib/entity.rb
index 3c21d90..d416d44 100644
--- a/lib/entity.rb
+++ b/lib/entity.rb
@@ -167,8 +167,8 @@ class IMICRTS
     end
 
     def draw_radius
-      Gosu.draw_circle(@position.x, @position.y, @radius, ZOrder::ENTITY_RADIUS, @player.color, 360 / 18)
-      Gosu.draw_circle(@position.x, @position.y, @boid_radius, ZOrder::ENTITY_RADIUS, @player.color, 360 / 18)
+      Gosu.draw_arc(@position.x, @position.y, @radius, 1.0, 18, 1, @player.color, ZOrder::ENTITY_RADIUS)
+      Gosu.draw_arc(@position.x, @position.y, @boid_radius, 1.0, 18, 1, @player.color, ZOrder::ENTITY_RADIUS)
     end
 
     def draw_gizmos
diff --git a/lib/window.rb b/lib/window.rb
index f0b502c..a2fb4e8 100644
--- a/lib/window.rb
+++ b/lib/window.rb
@@ -1,5 +1,5 @@
 class IMICRTS
-  class Window < CyberarmEngine::Engine
+  class Window < CyberarmEngine::Window
     attr_reader :mouse
     def setup
       @last_update_time = Gosu.milliseconds
@@ -52,4 +52,4 @@ class IMICRTS
       super(*args)
     end
   end
-end
\ No newline at end of file
+end