diff --git a/src/Workspaces/CSharp/Portable/Simplification/CSharpSimplificationService.Expander.cs b/src/Workspaces/CSharp/Portable/Simplification/CSharpSimplificationService.Expander.cs
index 4d64768700de3448e33c69c30f152f8a18c2ac57..5a4e6d5f49d6cc07e72d80206ac49282ef325391 100644
--- a/src/Workspaces/CSharp/Portable/Simplification/CSharpSimplificationService.Expander.cs
+++ b/src/Workspaces/CSharp/Portable/Simplification/CSharpSimplificationService.Expander.cs
@@ -197,7 +197,9 @@ public override SyntaxNode VisitParenthesizedLambdaExpression(ParenthesizedLambd
                                 {
                                     var typeSyntax = parameterSymbols[i].Type.GenerateTypeSyntax().WithTrailingTrivia(s_oneWhitespaceSeparator);
                                     var newParameter = parameters[i].WithType(typeSyntax).WithAdditionalAnnotations(Simplifier.Annotation);
-                                    newParameters = newParameters.Replace(parameters[i], newParameter);
+
+                                    var currentParameter = newParameters[i];
+                                    newParameters = newParameters.Replace(currentParameter, newParameter);
                                 }
 
                                 var newParameterList = parameterList.WithParameters(newParameters);