diff --git a/MarkMpn.Sql4Cds.Engine.Tests/ExecutionPlanTests.cs b/MarkMpn.Sql4Cds.Engine.Tests/ExecutionPlanTests.cs
index ecd31ba7..7d27464d 100644
--- a/MarkMpn.Sql4Cds.Engine.Tests/ExecutionPlanTests.cs
+++ b/MarkMpn.Sql4Cds.Engine.Tests/ExecutionPlanTests.cs
@@ -6062,6 +6062,62 @@ public void FilterAuditOnLeftJoinColumn()
                 </fetch>");
         }
 
+        [TestMethod]
+        public void FilterAuditOnUserId()
+        {
+            var planBuilder = new ExecutionPlanBuilder(_dataSources.Values, new OptionsWrapper(this) { PrimaryDataSource = "prod" });
+            var query = "SELECT * FROM audit WHERE userid = 'B52C0694-E16F-40CD-9F27-800023C47A98'";
+            var plans = planBuilder.Build(query, null, out _);
+
+            Assert.AreEqual(1, plans.Length);
+            var select = AssertNode<SelectNode>(plans[0]);
+            var fetch = AssertNode<FetchXmlScan>(select.Source);
+            AssertFetchXml(fetch, @"
+                <fetch xmlns:generator='MarkMpn.SQL4CDS'>
+                    <entity name='audit'>
+                        <all-attributes />
+                        <filter>
+                            <condition attribute='userid' operator='eq' value='B52C0694-E16F-40CD-9F27-800023C47A98' />
+                        </filter>
+                    </entity>
+                </fetch>");
+        }
+
+        [TestMethod]
+        public void FilterAuditOnUserIdAggregate()
+        {
+            // Can do aggregates on audit table when any filtering is done only on the table itself,
+            // not on any joins
+            var planBuilder = new ExecutionPlanBuilder(_dataSources.Values, new OptionsWrapper(this) { PrimaryDataSource = "prod" });
+            var query = "SELECT COUNT(*) FROM audit WHERE userid = 'B52C0694-E16F-40CD-9F27-800023C47A98'";
+            var plans = planBuilder.Build(query, null, out _);
+
+            Assert.AreEqual(1, plans.Length);
+            var select = AssertNode<SelectNode>(plans[0]);
+            var tryCatch = AssertNode<TryCatchNode>(select.Source);
+            var aggregateFetch = AssertNode<FetchXmlScan>(tryCatch.TrySource);
+            AssertFetchXml(aggregateFetch, @"
+                <fetch xmlns:generator='MarkMpn.SQL4CDS' aggregate='true'>
+                    <entity name='audit'>
+                        <attribute name='auditid' aggregate='count' alias='count' />
+                        <filter>
+                            <condition attribute='userid' operator='eq' value='B52C0694-E16F-40CD-9F27-800023C47A98' />
+                        </filter>
+                    </entity>
+                </fetch>");
+            var streamAggregate = AssertNode<StreamAggregateNode>(tryCatch.CatchSource);
+            var fetch = AssertNode<FetchXmlScan>(streamAggregate.Source);
+            AssertFetchXml(fetch, @"
+                <fetch xmlns:generator='MarkMpn.SQL4CDS'>
+                    <entity name='audit'>
+                        <attribute name='auditid' />
+                        <filter>
+                            <condition attribute='userid' operator='eq' value='B52C0694-E16F-40CD-9F27-800023C47A98' />
+                        </filter>
+                    </entity>
+                </fetch>");
+        }
+
         [TestMethod]
         public void FilterAuditOnInnerJoinColumn()
         {
@@ -6087,6 +6143,33 @@ public void FilterAuditOnInnerJoinColumn()
                 </fetch>");
         }
 
+        [TestMethod]
+        public void FilterAuditOnInnerJoinColumnAggregate()
+        {
+            // Can't do aggregates on audit table when filtering is done on a join
+            // https://github.com/MarkMpn/Sql4Cds/issues/488
+            var planBuilder = new ExecutionPlanBuilder(_dataSources.Values, new OptionsWrapper(this) { PrimaryDataSource = "prod" });
+            var query = "SELECT COUNT(*) FROM audit INNER JOIN systemuser ON audit.userid = systemuser.systemuserid WHERE systemuser.domainname <> 'SYSTEM'";
+            var plans = planBuilder.Build(query, null, out _);
+
+            Assert.AreEqual(1, plans.Length);
+            var select = AssertNode<SelectNode>(plans[0]);
+            var aggregate = AssertNode<StreamAggregateNode>(select.Source);
+            var fetch = AssertNode<FetchXmlScan>(aggregate.Source);
+            AssertFetchXml(fetch, @"
+                <fetch xmlns:generator='MarkMpn.SQL4CDS'>
+                    <entity name='audit'>
+                        <attribute name='auditid' />
+                        <link-entity name='systemuser' from='systemuserid' to='userid' link-type='inner' alias='systemuser'>
+                            <filter>
+                                <condition attribute='domainname' operator='ne' value='SYSTEM' />
+                                <condition attribute='domainname' operator='not-null' />
+                            </filter>
+                        </link-entity>
+                    </entity>
+                </fetch>");
+        }
+
         [TestMethod]
         public void SortAuditOnJoinColumn()
         {
diff --git a/MarkMpn.Sql4Cds.Engine/ExecutionPlan/HashMatchAggregateNode.cs b/MarkMpn.Sql4Cds.Engine/ExecutionPlan/HashMatchAggregateNode.cs
index 7c85b61b..98d8c4c4 100644
--- a/MarkMpn.Sql4Cds.Engine/ExecutionPlan/HashMatchAggregateNode.cs
+++ b/MarkMpn.Sql4Cds.Engine/ExecutionPlan/HashMatchAggregateNode.cs
@@ -340,6 +340,11 @@ Source is FetchXmlScan fetch &&
                     (fetchXml.Entity.name == "audit" || metadata[fetchXml.Entity.name].DataProviderId == DataProviders.ElasticDataProvider))
                     canUseFetchXmlAggregate = false;
 
+                // Aggregates on audit entity seem to transform inner joins to left outer joins, so can't
+                // use FetchXML aggregates here
+                if (fetchXml.Entity.name == "audit" && fetchXml.Entity.GetLinkEntities(true).Any())
+                    canUseFetchXmlAggregate = false;
+
                 var serializer = new XmlSerializer(typeof(FetchXml.FetchType));
 
                 if (canUseFetchXmlAggregate)