Mutable environments are a proposed addition to object-oriented languages, in which the environment in which a method runs can be changed from the defaults specified in its class. For this purpose, mutable methods are defined, some of which are predefined and are invoked at specific times. Others can be added by a programmer. A mutable method can be overridden by one or more environment objects, in whose scope a method runs. Mutable environments allow concerns for which aspect-oriented programming was developed to be addressed in a relatively simple framework, which is general enough to support wrappers around methods and error handling. This paper presents a first approximation to the idea, with some preliminary evaluation.