diff --git a/MANUAL.txt b/MANUAL.txt
index e0233b041..b8392a701 100644
--- a/MANUAL.txt
+++ b/MANUAL.txt
@@ -476,6 +476,8 @@ Reader options
      non-executable)
 
      2. `$DATADIR/filters` (executable or non-executable)
+     where `$DATADIR` is the user data directory (see
+     `--data-dir`, above).
 
      3. `$PATH` (executable only)