diff --git a/src/Polyfill/Nullability/NullabilityInfoContext.cs b/src/Polyfill/Nullability/NullabilityInfoContext.cs
index fc2dbe3e..42b0ef0f 100644
--- a/src/Polyfill/Nullability/NullabilityInfoContext.cs
+++ b/src/Polyfill/Nullability/NullabilityInfoContext.cs
@@ -222,7 +222,8 @@ public NullabilityInfo Create(PropertyInfo propertyInfo)
 
             if (setter != null)
             {
-                CheckNullabilityAttributes(nullability, setter.GetParameters()[^1].GetCustomAttributesData());
+                var parameters = setter.GetParameters();
+                CheckNullabilityAttributes(nullability, parameters[parameters.Length-1].GetCustomAttributesData());
             }
             else
             {