diff --git a/API.md b/API.md
index 7733599..08220b7 100644
--- a/API.md
+++ b/API.md
@@ -165,4 +165,5 @@ Returns how many entries have been viewed by a player.
   viewed entries
 
 #### Return value
-Amount of entries the player has viewed in the specified category.
+Amount of entries the player has viewed in the specified category. If the
+player does not exist, this function returns `nil`.