diff --git a/docs/common-pitfalls.md b/docs/common-pitfalls.md
index ad5a2d084..0f067132a 100644
--- a/docs/common-pitfalls.md
+++ b/docs/common-pitfalls.md
@@ -75,6 +75,10 @@ test(t => {
 });
 ```
 
+### Helpers are not compiled when using a non-default test folder
+
+This is a [known issue](https://github.com/avajs/ava/issues/1319). You should put your tests in a folder called `test` or `__tests__`.
+
 ---
 
 Is your problem not listed here? Submit a pull request or comment on [this issue](https://github.com/avajs/ava/issues/404).