diff --git a/vector/src/main/java/im/vector/riotx/features/pin/UnlockedActivity.kt b/vector/src/main/java/im/vector/riotx/features/pin/UnlockedActivity.kt
index 30f0755954..4177496154 100644
--- a/vector/src/main/java/im/vector/riotx/features/pin/UnlockedActivity.kt
+++ b/vector/src/main/java/im/vector/riotx/features/pin/UnlockedActivity.kt
@@ -16,4 +16,7 @@
 
 package im.vector.riotx.features.pin
 
+/**
+ * Tag class for activities that should not be protected by PIN code.
+ */
 interface UnlockedActivity