diff --git a/src/Microsoft.DotNet.Wpf/src/PresentationFramework/System/Windows/Markup/XmlnsCache.cs b/src/Microsoft.DotNet.Wpf/src/PresentationFramework/System/Windows/Markup/XmlnsCache.cs
index 44ad95cdd33..0d8d8ff9139 100644
--- a/src/Microsoft.DotNet.Wpf/src/PresentationFramework/System/Windows/Markup/XmlnsCache.cs
+++ b/src/Microsoft.DotNet.Wpf/src/PresentationFramework/System/Windows/Markup/XmlnsCache.cs
@@ -94,7 +94,7 @@ private void AddReferencedAssemblies()
             List<Assembly> interestingAssemblies = new List<Assembly>();
 
             // Load all the assemblies into a list.
-            foreach(string assemblyName in _assemblyPathTable.Keys.OfType<string>().OrderBy(s => s))
+            foreach(string assemblyName in _assemblyPathTable.Keys.OfType<string>().OrderBy(s => s, StringComparer.Ordinal))
             {
                 bool hasCacheInfo = true;
                 Assembly assy;