diff --git a/Bonsai.Core.Tests/TestWorkflow.cs b/Bonsai.Core.Tests/TestWorkflow.cs
index e2a9fa89..9dd00a97 100644
--- a/Bonsai.Core.Tests/TestWorkflow.cs
+++ b/Bonsai.Core.Tests/TestWorkflow.cs
@@ -122,6 +122,13 @@ public TestWorkflow AppendSubject<TSubjectBuilder>(string name)
             return Append(subjectBuilder);
         }
 
+        public TestWorkflow TopologicalSort()
+        {
+            var workflow = new ExpressionBuilderGraph();
+            workflow.InsertRange(0, Workflow.TopologicalSort());
+            return new TestWorkflow(workflow, Cursor);
+        }
+
         public ExpressionBuilderGraph ToInspectableGraph()
         {
             return Workflow.ToInspectableGraph();
diff --git a/Bonsai.Editor.Tests/WorkflowEditorTests.cs b/Bonsai.Editor.Tests/WorkflowEditorTests.cs
index 1a762e84..9c5bd031 100644
--- a/Bonsai.Editor.Tests/WorkflowEditorTests.cs
+++ b/Bonsai.Editor.Tests/WorkflowEditorTests.cs
@@ -48,12 +48,6 @@ static string ToString(IEnumerable<T> sequence)
             ExpressionBuilderGraph workflow = null,
             MockGraphView graphView = null)
         {
-            if (workflow != null)
-            {
-                // Workflows must be topologically sorted to ensure all editor operations are reversible
-                workflow.InsertRange(0, workflow.TopologicalSort());
-            }
-
             graphView ??= new MockGraphView(workflow);
             var editor = new WorkflowEditor(graphView.ServiceProvider, graphView);
             editor.UpdateLayout.Subscribe(graphView.UpdateGraphLayout);
@@ -236,7 +230,7 @@ public void ReplaceGraphNode_SingleInputWithVisualizerMapping_GroupWorkflowHasSi
                 .AppendBranch(source => source
                     .AppendSubject<Reactive.PublishSubject>("P")
                     .AddArguments(source.Append(new VisualizerMappingBuilder())))
-                .Workflow
+                .TopologicalSort()
                 .ToInspectableGraph();
 
             var (editor, assertIsReversible) = CreateMockEditor(workflow);
@@ -252,6 +246,7 @@ public void ReplaceGraphNode_SingleInputWithVisualizerMapping_GroupWorkflowHasSi
             var groupBuilder = ExpressionBuilder.Unwrap(groupNode?.Value) as GroupWorkflowBuilder;
             Assert.IsInstanceOfType(groupBuilder, typeof(GroupWorkflowBuilder));
             Assert.AreEqual(expected: 2, groupBuilder.Workflow.Count);
+            Assert.IsInstanceOfType(ExpressionBuilder.Unwrap(groupBuilder.Workflow[0].Value), typeof(WorkflowInputBuilder));
             Assert.IsInstanceOfType(ExpressionBuilder.Unwrap(groupBuilder.Workflow[1].Value), typeof(WorkflowOutputBuilder));
             assertIsReversible();
         }