Convert list of Objects to list of Interfaces

I have a class that inherits from an Interface.
public class MyClass : IMyInterface
The class implements the properties of the interface.
In business code, a method returns a list of MyClass objects. (List<MyClass> listOfObjects)
How can I convert this to a list of Interfaces eg List<IMyInterface> listOfInterfaces?
As the class implements the properties of the interface, I would hope this is straight forward!!!

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