diff --git a/CREDITS b/CREDITS
index ca7a57b..804c9a4 100644
--- a/CREDITS
+++ b/CREDITS
@@ -39,3 +39,8 @@ FediBlock-backend makes direct use of the following libraries and programs:
     From: The ICU project and community
           http://site.icu-project.org/
     License: BSD
+
+  fmt
+    From: Victor Zverovich, Jonathan Müller and community
+          https://fmt.dev/
+    License: MIT