diff --git a/CHANGELOG.md b/CHANGELOG.md
index 80a60002..71ca1d89 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -23,3 +23,12 @@ The following API changes should be documented as such:
 
 If possible, provide tooling that performs the changes, e.g. a shell-script.
 -->
+
+## API changes
+
+#### I/O
+
+To avoid using seqan3::io we changed the usage of the `seqan3::input_file_validator` and `seqan3::output_file_validator`
+, you now have to give the formats explicitly:
+`sharg::input_file_validator validator{std::vector{std::string{"exe"}, std::string{"fasta"}}};` and
+`sharg::output_file_validator validator{sharg::output_file_open_options::create_new, std::vector{std::string{"exe"}, std::string{"fasta"}}};`.