diff --git a/src/Microsoft.CodeAnalysis.Testing/Microsoft.CodeAnalysis.Analyzer.Testing/AnalyzerTest`1.cs b/src/Microsoft.CodeAnalysis.Testing/Microsoft.CodeAnalysis.Analyzer.Testing/AnalyzerTest`1.cs
index 566ca194c..80272b044 100644
--- a/src/Microsoft.CodeAnalysis.Testing/Microsoft.CodeAnalysis.Analyzer.Testing/AnalyzerTest`1.cs
+++ b/src/Microsoft.CodeAnalysis.Testing/Microsoft.CodeAnalysis.Analyzer.Testing/AnalyzerTest`1.cs
@@ -698,9 +698,7 @@ private static Diagnostic[] SortDistinctDiagnostics(IEnumerable<Diagnostic> diag
                 .OrderBy(d => d.Location.GetLineSpan().Path, StringComparer.Ordinal)
                 .ThenBy(d => d.Location.SourceSpan.Start)
                 .ThenBy(d => d.Location.SourceSpan.End)
-                .ThenBy(d => d.Id)
-                .ThenBy(d => d.GetMessage(), StringComparer.Ordinal)
-                .ToArray();
+                .ThenBy(d => d.Id).ToArray();
         }
 
         /// <summary>