diff --git a/README.md b/README.md
index 79a0431..f6ff5ad 100644
--- a/README.md
+++ b/README.md
@@ -31,3 +31,4 @@ a CalDAV/CardDAV server
 - Evolution
 - Apple Calendar
 - Home Assistant integration
+- Thunderbird
diff --git a/docs/index.md b/docs/index.md
index 31a5fee..fb4d933 100644
--- a/docs/index.md
+++ b/docs/index.md
@@ -27,3 +27,4 @@ a CalDAV/CardDAV server
 - Evolution
 - Apple Calendar
 - Home Assistant integration
+- Thunderbird