How can DBNull not equal DBNull

I have the following line of code ``` if (DBNull.Value.Equals(o) || o != null) ``` where `o` is `object o in row.ItemArray` I keep getting an error of --> `Xml type "List of xdt:untypedAtomic" does not support a conversion from Clr type "DBNull" to Clr type "String".` What I don't understand is that when I step through my code this `if` should be catching this and performing my alternate action but it does not? Can someone please shed some light for me. Thank you!