diff --git a/acl/src/main/java/org/springframework/security/acls/jdbc/BasicLookupStrategy.java b/acl/src/main/java/org/springframework/security/acls/jdbc/BasicLookupStrategy.java
index bd0110328b..4f424ac000 100644
--- a/acl/src/main/java/org/springframework/security/acls/jdbc/BasicLookupStrategy.java
+++ b/acl/src/main/java/org/springframework/security/acls/jdbc/BasicLookupStrategy.java
@@ -49,6 +49,7 @@ import org.springframework.security.acls.sid.PrincipalSid;
 import org.springframework.security.acls.sid.Sid;
 import org.springframework.security.util.FieldUtils;
 import org.springframework.util.Assert;
+import org.springframework.util.StringUtils;
 
 
 /**
@@ -293,10 +294,10 @@ public final class BasicLookupStrategy implements LookupStrategy {
                     for (int i = 0; i < objectIdentities.length; i++) {
                         // Determine prepared statement values for this iteration
                         String javaType = objectIdentities[i].getJavaType().getName();
-                        Assert.isInstanceOf(Long.class, objectIdentities[i].getIdentifier(),
-                            "This class requires ObjectIdentity.getIdentifier() to be a Long");
 
-                        long id = ((Long) objectIdentities[i].getIdentifier()).longValue();
+                        // No need to check for nulls, as guaranteed non-null by ObjectIdentity.getIdentifier() interface contract
+                        String identifier = objectIdentities[i].getIdentifier().toString();
+                        long id = (Long.valueOf(identifier)).longValue();
 
                         // Inject values
                         ps.setLong((2 * i) + 1, id);
diff --git a/acl/src/main/java/org/springframework/security/acls/objectidentity/ObjectIdentityImpl.java b/acl/src/main/java/org/springframework/security/acls/objectidentity/ObjectIdentityImpl.java
index b7d79e1114..cf5fb7ac29 100644
--- a/acl/src/main/java/org/springframework/security/acls/objectidentity/ObjectIdentityImpl.java
+++ b/acl/src/main/java/org/springframework/security/acls/objectidentity/ObjectIdentityImpl.java
@@ -15,6 +15,7 @@
 package org.springframework.security.acls.objectidentity;
 
 import org.springframework.security.acls.IdentityUnavailableException;
+import org.springframework.security.acls.jdbc.LookupStrategy;
 
 import org.springframework.util.Assert;
 import org.springframework.util.ClassUtils;
@@ -97,6 +98,12 @@ public class ObjectIdentityImpl implements ObjectIdentity {
     /**
      * Important so caching operates properly.<P>Considers an object of the same class equal if it has the same
      * <code>classname</code> and <code>id</code> properties.</p>
+     * 
+     * <p>
+     * Note that this class uses string equality for the identifier field, which ensures it better supports
+     * differences between {@link LookupStrategy} requirements and the domain object represented by this
+     * <code>ObjectIdentityImpl</code>.
+     * </p>
      *
      * @param arg0 object to compare
      *
@@ -113,7 +120,7 @@ public class ObjectIdentityImpl implements ObjectIdentity {
 
         ObjectIdentityImpl other = (ObjectIdentityImpl) arg0;
 
-        if (this.getIdentifier().equals(other.getIdentifier()) && this.getJavaType().equals(other.getJavaType())) {
+        if (this.getIdentifier().toString().equals(other.getIdentifier().toString()) && this.getJavaType().equals(other.getJavaType())) {
             return true;
         }
 
diff --git a/acl/src/test/java/org/springframework/security/acls/jdbc/BasicLookupStrategyTests.java b/acl/src/test/java/org/springframework/security/acls/jdbc/BasicLookupStrategyTests.java
index 9d25edfd73..2c1d5a84c7 100644
--- a/acl/src/test/java/org/springframework/security/acls/jdbc/BasicLookupStrategyTests.java
+++ b/acl/src/test/java/org/springframework/security/acls/jdbc/BasicLookupStrategyTests.java
@@ -120,7 +120,8 @@ public class BasicLookupStrategyTests {
     public void testAclsRetrievalWithDefaultBatchSize() throws Exception {
         ObjectIdentity topParentOid = new ObjectIdentityImpl("org.springframework.security.TargetObject", new Long(100));
         ObjectIdentity middleParentOid = new ObjectIdentityImpl("org.springframework.security.TargetObject", new Long(101));
-        ObjectIdentity childOid = new ObjectIdentityImpl("org.springframework.security.TargetObject", new Long(102));
+        // Deliberately use an integer for the child, to reproduce bug report in SEC-819
+        ObjectIdentity childOid = new ObjectIdentityImpl("org.springframework.security.TargetObject", new Integer(102));
 
         Map map = this.strategy.readAclsById(new ObjectIdentity[] { topParentOid, middleParentOid, childOid }, null);
         checkEntries(topParentOid, middleParentOid, childOid, map);
@@ -128,7 +129,7 @@ public class BasicLookupStrategyTests {
 
     @Test
     public void testAclsRetrievalFromCacheOnly() throws Exception {
-        ObjectIdentity topParentOid = new ObjectIdentityImpl("org.springframework.security.TargetObject", new Long(100));
+        ObjectIdentity topParentOid = new ObjectIdentityImpl("org.springframework.security.TargetObject", new Integer(100));
         ObjectIdentity middleParentOid = new ObjectIdentityImpl("org.springframework.security.TargetObject", new Long(101));
         ObjectIdentity childOid = new ObjectIdentityImpl("org.springframework.security.TargetObject", new Long(102));
 
@@ -145,7 +146,7 @@ public class BasicLookupStrategyTests {
     @Test
     public void testAclsRetrievalWithCustomBatchSize() throws Exception {
         ObjectIdentity topParentOid = new ObjectIdentityImpl("org.springframework.security.TargetObject", new Long(100));
-        ObjectIdentity middleParentOid = new ObjectIdentityImpl("org.springframework.security.TargetObject", new Long(101));
+        ObjectIdentity middleParentOid = new ObjectIdentityImpl("org.springframework.security.TargetObject", new Integer(101));
         ObjectIdentity childOid = new ObjectIdentityImpl("org.springframework.security.TargetObject", new Long(102));
 
         // Set a batch size to allow multiple database queries in order to retrieve all acls
@@ -227,7 +228,7 @@ public class BasicLookupStrategyTests {
         jdbcTemplate.execute(query);
         
         ObjectIdentity topParentOid = new ObjectIdentityImpl("org.springframework.security.TargetObject", new Long(100));
-        ObjectIdentity middleParentOid = new ObjectIdentityImpl("org.springframework.security.TargetObject", new Long(101));
+        ObjectIdentity middleParentOid = new ObjectIdentityImpl("org.springframework.security.TargetObject", new Integer(101));
         ObjectIdentity childOid = new ObjectIdentityImpl("org.springframework.security.TargetObject", new Long(102));
         ObjectIdentity middleParent2Oid = new ObjectIdentityImpl("org.springframework.security.TargetObject", new Long(103));
         
@@ -260,8 +261,8 @@ public class BasicLookupStrategyTests {
 
         ObjectIdentity grandParentOid = new ObjectIdentityImpl("org.springframework.security.TargetObject", new Long(104));
         ObjectIdentity parent1Oid = new ObjectIdentityImpl("org.springframework.security.TargetObject", new Long(105));
-        ObjectIdentity parent2Oid = new ObjectIdentityImpl("org.springframework.security.TargetObject", new Long(106));
-        ObjectIdentity childOid = new ObjectIdentityImpl("org.springframework.security.TargetObject", new Long(107));
+        ObjectIdentity parent2Oid = new ObjectIdentityImpl("org.springframework.security.TargetObject", new Integer(106));
+        ObjectIdentity childOid = new ObjectIdentityImpl("org.springframework.security.TargetObject", new Integer(107));
 
         // First lookup only child, thus populating the cache with grandParent, parent1 and child
         Permission[] checkPermission = new Permission[] { BasePermission.READ };
@@ -290,21 +291,4 @@ public class BasicLookupStrategyTests {
         Assert.assertTrue(foundParent2Acl.isGranted(checkPermission, sids, false));
     }
     
-    @Test
-    public void testAclsWithDifferentSerializableTypesAsObjectIdentities() throws Exception {
-        String query = "INSERT INTO acl_object_identity(ID,OBJECT_ID_CLASS,OBJECT_ID_IDENTITY,PARENT_OBJECT,OWNER_SID,ENTRIES_INHERITING) VALUES (4,2,104,null,1,1);"
-                + "INSERT INTO acl_entry(ID,ACL_OBJECT_IDENTITY,ACE_ORDER,SID,MASK,GRANTING,AUDIT_SUCCESS,AUDIT_FAILURE) VALUES (5,4,0,1,1,1,0,0)";
-        jdbcTemplate.execute(query);
-
-        ObjectIdentity oid = new ObjectIdentityImpl("org.springframework.security.TargetObject", new Integer(104));
-        Sid[] sids = new Sid[] { new PrincipalSid("ben") };
-        ObjectIdentity[] childOids = new ObjectIdentity[] { oid };
-        
-        try {
-            Map foundAcls = strategy.readAclsById(childOids, sids);
-            Assert.fail("It should have thrown IllegalArgumentException");
-        } catch(IllegalArgumentException expected) {
-            Assert.assertTrue(true);
-        }
-    }
 }
\ No newline at end of file
diff --git a/acl/src/test/java/org/springframework/security/acls/jdbc/JdbcAclServiceTests.java b/acl/src/test/java/org/springframework/security/acls/jdbc/JdbcAclServiceTests.java
index 5c7cf6214c..d4ac82c695 100644
--- a/acl/src/test/java/org/springframework/security/acls/jdbc/JdbcAclServiceTests.java
+++ b/acl/src/test/java/org/springframework/security/acls/jdbc/JdbcAclServiceTests.java
@@ -97,7 +97,7 @@ public class JdbcAclServiceTests extends AbstractTransactionalDataSourceSpringCo
 
         ObjectIdentity topParentOid = new ObjectIdentityImpl("org.springframework.security.TargetObject", new Long(100));
         ObjectIdentity middleParentOid = new ObjectIdentityImpl("org.springframework.security.TargetObject", new Long(101));
-        ObjectIdentity childOid = new ObjectIdentityImpl("org.springframework.security.TargetObject", new Long(102));
+        ObjectIdentity childOid = new ObjectIdentityImpl("org.springframework.security.TargetObject", new Integer(102));
 
         MutableAcl topParent = jdbcMutableAclService.createAcl(topParentOid);
         MutableAcl middleParent = jdbcMutableAclService.createAcl(middleParentOid);
@@ -337,7 +337,7 @@ public class JdbcAclServiceTests extends AbstractTransactionalDataSourceSpringCo
 
         ObjectIdentity topParentOid = new ObjectIdentityImpl("org.springframework.security.TargetObject", new Long(100));
         ObjectIdentity middleParentOid = new ObjectIdentityImpl("org.springframework.security.TargetObject", new Long(101));
-        ObjectIdentity childOid = new ObjectIdentityImpl("org.springframework.security.TargetObject", new Long(102));
+        ObjectIdentity childOid = new ObjectIdentityImpl("org.springframework.security.TargetObject", new Integer(102));
         
         // Remove the child and check all related database rows were removed accordingly
         jdbcMutableAclService.deleteAcl(childOid, false);