diff --git a/ldap/src/main/java/org/springframework/security/ldap/userdetails/LdapUserDetailsImpl.java b/ldap/src/main/java/org/springframework/security/ldap/userdetails/LdapUserDetailsImpl.java
index 4eb5608b65..6e58c1f22a 100644
--- a/ldap/src/main/java/org/springframework/security/ldap/userdetails/LdapUserDetailsImpl.java
+++ b/ldap/src/main/java/org/springframework/security/ldap/userdetails/LdapUserDetailsImpl.java
@@ -34,11 +34,13 @@ import org.springframework.util.Assert;
  * distinguished name and a set of attributes that have been retrieved from the Ldap server.
  * <p>
  * An instance may be created as the result of a search, or when user information is retrieved during authentication.
- * </p>
  * <p>
  * An instance of this class will be used by the <tt>LdapAuthenticationProvider</tt> to construct the final user details
  * object that it returns.
- * </p>
+ * <p>
+ * The {@code equals} and {@code hashcode} methods are implemented using the {@code Dn} property and do not consider
+ * additional state, so it is not possible two store two instances with the same DN in the same set, or use them as
+ * keys in a map.
  *
  * @author Luke Taylor
  */
@@ -104,14 +106,28 @@ public class LdapUserDetailsImpl implements LdapUserDetails, PasswordPolicyData
         return graceLoginsRemaining;
     }
 
+    @Override
+    public boolean equals(Object obj) {
+        if (obj instanceof LdapUserDetailsImpl) {
+            return dn.equals(((LdapUserDetailsImpl)obj).dn);
+        }
+        return false;
+    }
+
+    @Override
+    public int hashCode() {
+        return dn.hashCode();
+    }
+
     public String toString() {
         StringBuilder sb = new StringBuilder();
         sb.append(super.toString()).append(": ");
+        sb.append("Dn: ").append(dn).append("; ");
         sb.append("Username: ").append(this.username).append("; ");
         sb.append("Password: [PROTECTED]; ");
         sb.append("Enabled: ").append(this.enabled).append("; ");
         sb.append("AccountNonExpired: ").append(this.accountNonExpired).append("; ");
-        sb.append("credentialsNonExpired: ").append(this.credentialsNonExpired).append("; ");
+        sb.append("CredentialsNonExpired: ").append(this.credentialsNonExpired).append("; ");
         sb.append("AccountNonLocked: ").append(this.accountNonLocked).append("; ");
 
         if (this.getAuthorities() != null) {
diff --git a/ldap/src/test/java/org/springframework/security/ldap/userdetails/InetOrgPersonTests.java b/ldap/src/test/java/org/springframework/security/ldap/userdetails/InetOrgPersonTests.java
index 8ccf3615ab..4255ba5b3d 100644
--- a/ldap/src/test/java/org/springframework/security/ldap/userdetails/InetOrgPersonTests.java
+++ b/ldap/src/test/java/org/springframework/security/ldap/userdetails/InetOrgPersonTests.java
@@ -1,16 +1,20 @@
 package org.springframework.security.ldap.userdetails;
 
-import junit.framework.TestCase;
+import static org.junit.Assert.*;
 
+import java.util.HashSet;
+import java.util.Set;
+
+import org.junit.Test;
 import org.springframework.ldap.core.DirContextAdapter;
 import org.springframework.ldap.core.DistinguishedName;
-import org.springframework.security.ldap.userdetails.InetOrgPerson;
 
 /**
  * @author Luke Taylor
  */
-public class InetOrgPersonTests extends TestCase {
+public class InetOrgPersonTests {
 
+    @Test
     public void testUsernameIsMappedFromContextUidIfNotSet() {
         InetOrgPerson.Essence essence = new InetOrgPerson.Essence(createUserContext());
         InetOrgPerson p = (InetOrgPerson) essence.createUserDetails();
@@ -18,7 +22,19 @@ public class InetOrgPersonTests extends TestCase {
         assertEquals("ghengis", p.getUsername());
     }
 
-    public void testUsernameIsDifferentFromContextUidIfSet() {
+    @Test
+    public void hashLookupViaEqualObjectRetrievesOriginal() throws Exception {
+        InetOrgPerson.Essence essence = new InetOrgPerson.Essence(createUserContext());
+        InetOrgPerson p = (InetOrgPerson) essence.createUserDetails();
+        essence = new InetOrgPerson.Essence(createUserContext());
+        InetOrgPerson p2 = (InetOrgPerson) essence.createUserDetails();
+        Set<InetOrgPerson> set =  new HashSet<InetOrgPerson>();
+        set.add(p);
+        assertTrue(set.contains(p2));
+    }
+
+    @Test
+    public void usernameIsDifferentFromContextUidIfSet() {
         InetOrgPerson.Essence essence = new InetOrgPerson.Essence(createUserContext());
         essence.setUsername("joe");
         InetOrgPerson p = (InetOrgPerson) essence.createUserDetails();
@@ -27,7 +43,8 @@ public class InetOrgPersonTests extends TestCase {
         assertEquals("ghengis", p.getUid());
     }
 
-    public void testAttributesMapCorrectlyFromContext() {
+    @Test
+    public void attributesMapCorrectlyFromContext() {
         InetOrgPerson.Essence essence = new InetOrgPerson.Essence(createUserContext());
         InetOrgPerson p = (InetOrgPerson) essence.createUserDetails();
 
@@ -50,6 +67,7 @@ public class InetOrgPersonTests extends TestCase {
         assertEquals("G", p.getInitials());
     }
 
+    @Test
     public void testPasswordIsSetFromContextUserPassword() {
         InetOrgPerson.Essence essence = new InetOrgPerson.Essence(createUserContext());
         InetOrgPerson p = (InetOrgPerson) essence.createUserDetails();
@@ -57,7 +75,8 @@ public class InetOrgPersonTests extends TestCase {
         assertEquals("pillage", p.getPassword());
     }
 
-    public void testMappingBackToContextMatchesOriginalData() {
+    @Test
+    public void mappingBackToContextMatchesOriginalData() {
         DirContextAdapter ctx1 = createUserContext();
         DirContextAdapter ctx2 = new DirContextAdapter();
         ctx1.setAttributeValues("objectclass", new String[] {"top", "person", "organizationalPerson", "inetOrgPerson"});
@@ -68,7 +87,8 @@ public class InetOrgPersonTests extends TestCase {
         assertEquals(ctx1, ctx2);
     }
 
-    public void testCopyMatchesOriginalData() {
+    @Test
+    public void copyMatchesOriginalData() {
         DirContextAdapter ctx1 = createUserContext();
         DirContextAdapter ctx2 = new DirContextAdapter();
         ctx2.setDn(new DistinguishedName("ignored=ignored"));