diff --git a/docs/4.0/migration.md b/docs/4.0/migration.md
index 7b4199fa04f05aa5d7066f94325ad25581fc17bc..3930639377ec44c3125f3003295c8045529a8a0b 100644
--- a/docs/4.0/migration.md
+++ b/docs/4.0/migration.md
@@ -10,6 +10,7 @@ toc: true
 While in beta, we aim to have no breaking changes. However, things don't always go as planned. Below are the breaking changes to bear in mind when moving from Beta 1 to Beta 2.
 
 - Removed `$badge-color` variable and its usage on `.badge`. We use a color contrast function to pick a `color` based on the `background-color`, so the variable is unnecessary.
+- Renamed `grayscale()` function to `gray()` to avoid breaking conflict with the CSS native `grayscale` filter.
 
 
 ## Summary