diff --git a/src/Umbraco.Examine.Lucene/UmbracoExamineIndex.cs b/src/Umbraco.Examine.Lucene/UmbracoExamineIndex.cs
index 6440c7bd6a..9e6c414344 100644
--- a/src/Umbraco.Examine.Lucene/UmbracoExamineIndex.cs
+++ b/src/Umbraco.Examine.Lucene/UmbracoExamineIndex.cs
@@ -107,12 +107,26 @@ namespace Umbraco.Cms.Infrastructure.Examine
         {
             if (CanInitialize())
             {
-                // Use SafeCallContext to prevent the current Execution Context (AsyncLocal) flow to child
+                // Use ExecutionContext.SuppressFlow to prevent the current Execution Context (AsyncLocal) flow to child
                 // tasks executed in the base class so we don't leak Scopes.
                 // TODO: See notes at the top of this class
                 using (ExecutionContext.SuppressFlow())
                 {
                     base.PerformDeleteFromIndex(itemIds, onComplete);
+                }
+            }
+        }
+
+        protected override void PerformIndexItems(IEnumerable<ValueSet> values, Action<IndexOperationEventArgs> onComplete)
+        {
+            if (CanInitialize())
+            {
+                // Use ExecutionContext.SuppressFlow to prevent the current Execution Context (AsyncLocal) flow to child
+                // tasks executed in the base class so we don't leak Scopes.
+                // TODO: See notes at the top of this class
+                using (ExecutionContext.SuppressFlow())
+                {
+                    base.PerformIndexItems(values, onComplete);
                 }                
             }
         }
diff --git a/src/Umbraco.Infrastructure/Scoping/Scope.cs b/src/Umbraco.Infrastructure/Scoping/Scope.cs
index e7ec3df4f7..603a83c197 100644
--- a/src/Umbraco.Infrastructure/Scoping/Scope.cs
+++ b/src/Umbraco.Infrastructure/Scoping/Scope.cs
@@ -433,7 +433,7 @@ namespace Umbraco.Cms.Core.Scoping
 
             if (this != _scopeProvider.AmbientScope)
             {
-                var failedMessage = $"The {nameof(Scope)} {this.GetDebugInfo()} being disposed is not the Ambient {nameof(Scope)} {_scopeProvider.AmbientScope.GetDebugInfo()}. This typically indicates that a child {nameof(Scope)} was not disposed or flowed to a child thread that was not re-joined to the thread that the parent originated (i.e. Task.Run used as a fire and forget task without ExecutionContext.SuppressFlow()).";
+                var failedMessage = $"The {nameof(Scope)} {this.GetDebugInfo()} being disposed is not the Ambient {nameof(Scope)} {_scopeProvider.AmbientScope.GetDebugInfo()}. This typically indicates that a child {nameof(Scope)} was not disposed, or flowed to a child thread that was not awaited, or concurrent threads are accessing the same {nameof(Scope)} (Ambient context) which is not supported. If using Task.Run (or similar) as a fire and forget tasks or to run threads in parallel you must suppress execution context flow with ExecutionContext.SuppressFlow() and ExecutionContext.RestoreFlow().";
 
 #if DEBUG_SCOPES
                 Scope ambient = _scopeProvider.AmbientScope;
diff --git a/src/Umbraco.Tests.Integration/Umbraco.Infrastructure/Scoping/ScopeTests.cs b/src/Umbraco.Tests.Integration/Umbraco.Infrastructure/Scoping/ScopeTests.cs
index 5a08d0c4b5..7b3075eeb9 100644
--- a/src/Umbraco.Tests.Integration/Umbraco.Infrastructure/Scoping/ScopeTests.cs
+++ b/src/Umbraco.Tests.Integration/Umbraco.Infrastructure/Scoping/ScopeTests.cs
@@ -129,12 +129,12 @@ namespace Umbraco.Cms.Tests.Integration.Umbraco.Infrastructure.Scoping
                 Console.WriteLine("Child Task after disposed: " + scopeProvider.AmbientScope.InstanceId);
             });
 
-            Thread.Sleep(2000); // block for a bit to ensure the child task is disposed first
+            Console.WriteLine("Parent Task waiting: " + scopeProvider.AmbientScope?.InstanceId);
+            Task.WaitAll(t);
             Console.WriteLine("Parent Task disposing: " + scopeProvider.AmbientScope.InstanceId);
             mainScope.Dispose();
             Console.WriteLine("Parent Task disposed: " + scopeProvider.AmbientScope?.InstanceId);
 
-            Task.WaitAll(t);
             Assert.Pass();
         }