diff --git a/README.md b/README.md
index 0cc7a64..38bb622 100644
--- a/README.md
+++ b/README.md
@@ -20,6 +20,8 @@ Creating and maintaining open-source modules is a lot of work. A donation is als
 
 The constructor for `validatem`'s `ValidationError` type. This is invoked like any other `Error` constructor, but you may optionally pass extra metadata that should be stored on the error.
 
+__Note that, for performance reasons (preventing stacktrace collection), the returned object does not *actually* inherit from `Error`!__ This should not affect its correct functioning, considering that the stacktraces of individual validators are not used in Validatem, and `ValidationError`s should never be thrown outside of a validator context anyway.
+
 __Unless you are implementing a parser and using virtual properties, you probably do not need to specify the `path` property.__ Combinators like `arrayOf` will insert their path segments after-the-fact by themselves, your validator does not need to do this.
 
 * __message:__ A description of the validation problem. This should be formatted in such a way that it describes the *requirement*, and *not* how it failed; for example, it should say "Must be a string" rather than "Is not a string".