diff --git a/ILSpy.Tests/Views/DebugStepsTests.cs b/ILSpy.Tests/Views/DebugStepsTests.cs
index 1413e30ac..39014f515 100644
--- a/ILSpy.Tests/Views/DebugStepsTests.cs
+++ b/ILSpy.Tests/Views/DebugStepsTests.cs
@@ -288,6 +288,49 @@ public class DebugStepsTests
 		return Task.CompletedTask;
 	}
 
+	[AvaloniaTest]
+	public Task MarkNodeStart_Excludes_Leading_Indentation()
+	{
+		// A node opened at the start of an indented line must record its range from the first real
+		// character, so the debug-step highlight does not extend across the indentation to column 0.
+		var output = new AvaloniaEditTextOutput();
+		output.Indent();
+		output.WriteLine();
+
+		var node = new object();
+		output.MarkNodeStart(node);
+		output.Write("statement;");
+		output.MarkNodeEnd(node);
+
+		output.NodeLookup.TryGetRange(node, out var range).Should().BeTrue();
+		output.GetText().Substring(range.Start, range.Length).Should().Be("statement;");
+		return Task.CompletedTask;
+	}
+
+	[AvaloniaTest]
+	public Task MarkNodeEnd_Records_Nodes_Regardless_Of_Close_Order()
+	{
+		// Node spans are keyed by identity, so closing an outer node before the inner one it still
+		// contains must not discard either range. A stack that popped by position would lose both.
+		var output = new AvaloniaEditTextOutput();
+		var outer = new object();
+		var inner = new object();
+
+		output.MarkNodeStart(outer);
+		output.Write("a(");
+		output.MarkNodeStart(inner);
+		output.Write("b");
+		output.MarkNodeEnd(outer);
+		output.Write(")");
+		output.MarkNodeEnd(inner);
+
+		output.NodeLookup.TryGetRange(outer, out var outerRange).Should().BeTrue();
+		output.GetText().Substring(outerRange.Start, outerRange.Length).Should().Be("a(b");
+		output.NodeLookup.TryGetRange(inner, out var innerRange).Should().BeTrue();
+		output.GetText().Substring(innerRange.Start, innerRange.Length).Should().Be("b)");
+		return Task.CompletedTask;
+	}
+
 	[AvaloniaTest]
 	public Task Pane_Reports_Not_Available_For_Languages_Without_Debug_Steps()
 	{
diff --git a/ILSpy/TextView/AvaloniaEditTextOutput.cs b/ILSpy/TextView/AvaloniaEditTextOutput.cs
index 3ad943b1c..7c3c25f2a 100644
--- a/ILSpy/TextView/AvaloniaEditTextOutput.cs
+++ b/ILSpy/TextView/AvaloniaEditTextOutput.cs
@@ -54,7 +54,10 @@ namespace ICSharpCode.ILSpy.TextView
 		public int LengthLimit { get; set; } = int.MaxValue;
 
 		readonly Stack<(int Offset, HighlightingColor Color)> openSpans = new();
-		readonly Stack<(object Node, int Offset)> openNodes = new();
+		// Keyed by node rather than a stack: node writes are strictly nested today, but keying by
+		// identity means a stray or out-of-order MarkNodeEnd is a clean no-op that can't desync the
+		// remaining open nodes. Each node is written exactly once, so there is no self-nesting.
+		readonly Dictionary<object, int> openNodeStarts = new(ReferenceEqualityComparer.Instance);
 		readonly Stack<(NewFolding Folding, int StartLine)> openFoldings = new();
 		readonly List<NewFolding> foldings = new();
 		int indent;
@@ -290,6 +293,7 @@ namespace ICSharpCode.ILSpy.TextView
 
 		public void BeginSpan(HighlightingColor highlightingColor)
 		{
+			WriteIndentIfNeeded();
 			openSpans.Push((builder.Length, highlightingColor));
 		}
 
@@ -308,17 +312,17 @@ namespace ICSharpCode.ILSpy.TextView
 
 		public void MarkNodeStart(object node)
 		{
-			openNodes.Push((node, builder.Length));
+			// Flush a pending indent before capturing the offset so a node opened at the start of a
+			// line records its range from the first real character, not from column 0 across the
+			// leading indentation.
+			WriteIndentIfNeeded();
+			openNodeStarts[node] = builder.Length;
 		}
 
 		public void MarkNodeEnd(object node)
 		{
-			if (openNodes.Count == 0)
-				return;
-			var (currentNode, start) = openNodes.Pop();
-			if (!ReferenceEquals(currentNode, node))
-				return;
-			NodeLookup.AddNode(node, start, builder.Length - start);
+			if (openNodeStarts.Remove(node, out var start))
+				NodeLookup.AddNode(node, start, builder.Length - start);
 		}
 	}
 }