diff --git a/sandbox/src/test/java/org/springframework/ldap/authentication/ThreadLocalAuthenticationSourceTest.java b/sandbox/src/test/java/org/springframework/ldap/authentication/ThreadLocalAuthenticationSourceTest.java
new file mode 100644
index 00000000..ab092983
--- /dev/null
+++ b/sandbox/src/test/java/org/springframework/ldap/authentication/ThreadLocalAuthenticationSourceTest.java
@@ -0,0 +1,41 @@
+package org.springframework.ldap.authentication;
+
+import junit.framework.TestCase;
+
+public class ThreadLocalAuthenticationSourceTest extends TestCase {
+
+    private ThreadLocalAuthenticationSource tested;
+
+    protected void setUp() throws Exception {
+        ThreadLocalAuthenticationHolder.setPrincipal(null);
+        ThreadLocalAuthenticationHolder.setCredentials(null);
+
+        tested = new ThreadLocalAuthenticationSource();
+    }
+
+    public void testGetPrincipal() {
+        ThreadLocalAuthenticationHolder.setPrincipal("cn=john doe");
+        String result = tested.getPrincipal();
+
+        assertEquals("cn=john doe", result);
+    }
+
+    public void testGetPrincipal_NoDataBound() {
+        String result = tested.getPrincipal();
+
+        assertNull("Should be null", result);
+    }
+
+    public void testGetCredentials() {
+        ThreadLocalAuthenticationHolder.setCredentials("secret");
+        String result = tested.getCredentials();
+
+        assertEquals("secret", result);
+    }
+
+    public void testGetCredentials_NoDataBound() {
+        String result = tested.getCredentials();
+
+        assertNull("Should be null", result);
+    }
+}