diff --git a/src/main/java/dotsandboxes/DotsAndBoxesGrid.java b/src/main/java/dotsandboxes/DotsAndBoxesGrid.java
index a9e7c5b6639e8a2a8728809d9b17c8d155baf9b6..ded636deea69999972668f09d6564999c8ce879a 100644
--- a/src/main/java/dotsandboxes/DotsAndBoxesGrid.java
+++ b/src/main/java/dotsandboxes/DotsAndBoxesGrid.java
@@ -112,9 +112,14 @@ public class DotsAndBoxesGrid {
 
         // A box is complete if the north and south horizontals and the east and west verticals have all been drawn.
         // FIXME: You'll need to fix this code (after writing a test first).
-        return true;
+        if (getHorizontal(0, 0) && getHorizontal(0, 1) && getVertical(0, 0) && getVertical(1, 0)) {
+            return true;
+        }
+        else
+            return false;
     }
 
+
     /** Tries to claim a box for a player. If the box is complete, sets the ownership and returns true. */
     private boolean claimBox(int x, int y, int p) {
         if (boxComplete(x, y)) {
@@ -140,6 +145,7 @@ public class DotsAndBoxesGrid {
         }
 
         // FIXME: You need to throw an exception if the line was already drawn.
+        if (getHorizontal(x, y)) throw new IllegalStateException();
 
         this.horizontals[x][y] = true;