diff --git a/Src/Newtonsoft.Json/Converters/IsoDateTimeConverter.cs b/Src/Newtonsoft.Json/Converters/IsoDateTimeConverter.cs
index 0f90b870..fd562b69 100644
--- a/Src/Newtonsoft.Json/Converters/IsoDateTimeConverter.cs
+++ b/Src/Newtonsoft.Json/Converters/IsoDateTimeConverter.cs
@@ -136,7 +136,7 @@ namespace Newtonsoft.Json.Converters
             {
 #if !NET20
                 if (t == typeof(DateTimeOffset))
-                    return new DateTimeOffset((DateTime)reader.Value);
+                    return reader.Value is DateTimeOffset ? reader.Value : new DateTimeOffset((DateTime)reader.Value);
 #endif
 
                 return reader.Value;