diff --git a/src/Worm.java b/src/Worm.java
index ee6b529..bf5e7df 100644
--- a/src/Worm.java
+++ b/src/Worm.java
@@ -192,6 +192,9 @@ public class Worm {
      * 		|0 <= new.orientation < 2pi
      */
     public void turn(double angleToAdd) {
-    	assert 0 <= angleToAdd && angleToAdd < 2 * Math.PI;
+    	assert 0 <= angleToAdd && angleToAdd < (2 * Math.PI);
+    	if (0 <= (this.orientation + angleToAdd) && (this.orientation + angleToAdd) < (2 * Math.PI))
+    		setOrientation(this.orientation + angleToAdd);
+    	setOrientation((this.orientation + angleToAdd)%(2 * Math.PI));
     }
 }