diff --git a/src/coreclr/jit/sideeffects.cpp b/src/coreclr/jit/sideeffects.cpp
index 5f90c8d90456c7..a3f63b07e362ba 100644
--- a/src/coreclr/jit/sideeffects.cpp
+++ b/src/coreclr/jit/sideeffects.cpp
@@ -318,6 +318,19 @@ void AliasSet::AddNode(Compiler* compiler, GenTree* node)
     if (nodeInfo.IsLclVarWrite())
     {
         m_lclVarWrites.Add(compiler, nodeInfo.LclNum());
+
+        LclVarDsc* dsc = compiler->lvaGetDesc(nodeInfo.LclNum());
+        if (dsc->lvIsStructField)
+        {
+            m_lclVarWrites.Add(compiler, dsc->lvParentLcl);
+        }
+        else if (dsc->lvPromoted)
+        {
+            for (unsigned i = 0; i < dsc->lvFieldCnt; i++)
+            {
+                m_lclVarWrites.Add(compiler, dsc->lvFieldLclStart + i);
+            }
+        }
     }
 }
 
diff --git a/src/tests/JIT/Regression/JitBlue/Runtime_126414/Runtime_126414.cs b/src/tests/JIT/Regression/JitBlue/Runtime_126414/Runtime_126414.cs
new file mode 100644
index 00000000000000..f71b0d6e5f7ba4
--- /dev/null
+++ b/src/tests/JIT/Regression/JitBlue/Runtime_126414/Runtime_126414.cs
@@ -0,0 +1,60 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+using System;
+using System.Runtime.CompilerServices;
+using Xunit;
+
+namespace Runtime_126414;
+
+public readonly struct Endpoint
+{
+    public Endpoint(Endpoint e)
+    {
+        A = e.A;
+        B = e.B;
+        C = e.C;
+    }
+
+    public Endpoint(int a, int b, int c) { A = a; B = b; C = c; }
+
+    public int A { get; }
+    public int B { get; }
+    public int C { get; }
+}
+
+public sealed class Range
+{
+    private readonly Endpoint m_start;
+    private readonly Endpoint m_end;
+
+    // Using AggressiveOptimization to force reproduction of the bug which would eventually occur when tiered compilation optimizes the constructor
+    [MethodImpl(MethodImplOptions.AggressiveOptimization)]
+    public Range(Endpoint start, Endpoint end)
+    {
+        m_start = new Endpoint(start);  // Copy via copy constructor
+        m_end = new Endpoint(end);      // Copy via copy constructor
+    }
+
+    public int Length => m_end.A - m_start.A;
+}
+
+public class Program
+{
+    [Fact]
+    public static int TestEntryPoint()
+    {
+        const int expected = 5759;
+
+        var r = new Range(new Endpoint(100, 0, 0), new Endpoint(100 + expected, 0, 0));
+
+        if (r.Length != expected)
+        {
+            Console.WriteLine($"FAIL: Length={r.Length} (expected {expected}), hex=0x{r.Length:X}");
+            return 101;
+        }
+
+        Console.WriteLine($"PASS: Length = {expected}");
+        return 100;
+    }
+}
diff --git a/src/tests/JIT/Regression/JitBlue/Runtime_126414/Runtime_126414.csproj b/src/tests/JIT/Regression/JitBlue/Runtime_126414/Runtime_126414.csproj
new file mode 100644
index 00000000000000..501217e4d86892
--- /dev/null
+++ b/src/tests/JIT/Regression/JitBlue/Runtime_126414/Runtime_126414.csproj
@@ -0,0 +1,9 @@
+<Project Sdk="Microsoft.NET.Sdk">
+  <PropertyGroup>
+    <DebugType>None</DebugType>
+    <Optimize>True</Optimize>
+  </PropertyGroup>
+  <ItemGroup>
+    <Compile Include="$(MSBuildProjectName).cs" />
+  </ItemGroup>
+</Project>