diff --git a/lisp/textmodes/reftex-vars.el b/lisp/textmodes/reftex-vars.el
index ab085a3085a..a68a27bb07e 100644
--- a/lisp/textmodes/reftex-vars.el
+++ b/lisp/textmodes/reftex-vars.el
@@ -901,6 +901,7 @@ and the functions `TeX-current-macro' and
 `LaTeX-current-environment' are bound.  Also note that this
 feature might slow down the reftex parsing process for large TeX
 files."
+  :version "24.4"
   :group 'reftex-defining-label-environments
   :type '(repeat string))