diff --git a/src/test/java/dotsandboxes/DotsAndBoxesGridTest.java b/src/test/java/dotsandboxes/DotsAndBoxesGridTest.java
index 1946beda974d180686c65c0259a7b881e9a4eb5a..921e6443fb637ed96c336ea8bd77384d0a6e979e 100644
--- a/src/test/java/dotsandboxes/DotsAndBoxesGridTest.java
+++ b/src/test/java/dotsandboxes/DotsAndBoxesGridTest.java
@@ -28,4 +28,36 @@ public class DotsAndBoxesGridTest {
     }
 
     // FIXME: You need to write tests for the two known bugs in the code.
+    @Test
+    public void testBoxComplete() {
+        logger.info("Creating a new game");
+        DotsAndBoxesGrid grid = new DotsAndBoxesGrid(3, 5, 1);
+
+        logger.info("Drawing three of four box sides");
+        grid.drawHorizontal(0,0,1);
+        grid.drawHorizontal(1, 0, 1);
+        grid.drawVertical(0, 0, 1);
+
+        assertFalse(grid.boxComplete(0,0));
+
+        logger.info("Completing the box");
+        grid.drawVertical(0, 1, 1);
+
+        assertTrue(grid.boxComplete(0,0));
+    }
+
+    @Test
+    public void testLineDoubleUp() {
+        logger.info("Creating a new game");
+        DotsAndBoxesGrid gridTwo = new DotsAndBoxesGrid(3, 5, 1);
+
+        logger.info("Drawing a horizontal line");
+        gridTwo.drawHorizontal(1, 1, 1);
+        assertThrows(IllegalStateException.class, () -> gridTwo.drawHorizontal(1, 1, 1), "This horizontal line is already taken");
+
+        logger.info("Drawing a vertical line");
+        gridTwo.drawVertical(2, 2, 1);
+        assertThrows(IllegalStateException.class, () -> gridTwo.drawVertical(2, 2, 1), "This vertical line is already taken");
+    }
+
 }