diff --git a/CHANGELOG.md b/CHANGELOG.md
index 1d5a0246a..24aa810cd 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -6,6 +6,13 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## Unreleased
 
+### Special operations
+
+We added `application/ld+json` as acceptable MIME type for ActivityPub requests, so you'll need to recompile the `mime` library we use before recompiling Mobilizon:
+```
+MIX_ENV=prod mix deps.clean mime --build
+```
+
 ### Added
 
 - Possibility to login using LDAP