diff --git a/core/src/test/java/hudson/BulkChangeTest.java b/core/src/test/java/hudson/BulkChangeTest.java
new file mode 100644
index 0000000000..c7e34bd044
--- /dev/null
+++ b/core/src/test/java/hudson/BulkChangeTest.java
@@ -0,0 +1,92 @@
+package hudson;
+
+import hudson.model.Saveable;
+import junit.framework.TestCase;
+
+import java.io.IOException;
+
+/**
+ * Tests {@link BulkChange}.
+ *
+ * @author Kohsuke Kawaguchi
+ */
+public class BulkChangeTest extends TestCase {
+
+    private class Point implements Saveable {
+        /**
+         * Don't actually do any save, but just remember how many the actual I/O would have happened.
+         */
+        int saveCount = 0;
+
+        int x,y;
+
+        public void setX(int x) throws IOException {
+            this.x = x;
+            save();
+        }
+
+        public void setY(int y) throws IOException {
+            this.y = y;
+            save();
+        }
+
+        public void set(int x, int y) throws IOException {
+            setX(x);
+            setY(y);
+        }
+
+        public void save() throws IOException {
+            if(BulkChange.contains(this))   return;
+            saveCount++;
+        }
+    }
+
+    /**
+     * If there is no BulkChange, we should see two saves.
+     */
+    public void testNoBulkChange() throws Exception {
+        Point pt = new Point();
+        pt.set(0,0);
+        assertEquals(2,pt.saveCount);
+    }
+
+    /**
+     * With a {@link BulkChange}, this will become just one save.
+     */
+    public void testBulkChange() throws Exception {
+        Point pt = new Point();
+        BulkChange bc = new BulkChange(pt);
+        try {
+            pt.set(0,0);
+        } finally {
+            bc.commit();
+        }
+        assertEquals(1,pt.saveCount);
+    }
+
+    /**
+     * {@link BulkChange}s can be nested.
+     */
+    public void testNestedBulkChange() throws Exception {
+        Point pt = new Point();
+        Point _ = new Point();
+        BulkChange bc1 = new BulkChange(pt);
+        try {
+            BulkChange bc2 = new BulkChange(_);
+            try {
+                BulkChange bc3 = new BulkChange(pt);
+                try {
+                    pt.set(0,0);
+                } finally {
+                    bc3.commit();
+                }
+            } finally {
+                bc2.commit();
+            }
+            pt.set(0,0);
+        } finally {
+            bc1.commit();
+        }
+        assertEquals(1,pt.saveCount);
+    }
+}