diff --git a/tex/crossrefenum.sty b/tex/crossrefenum.sty
index 3d6ca15..808f04f 100644
--- a/tex/crossrefenum.sty
+++ b/tex/crossrefenum.sty
@@ -1,3 +1,6 @@
+% This file cannot be loaded in main-test.tex for it would load the version of crossrefenum.tex
+% installed in the texmf tree.
+% As a consequence, it should not be changed to correct bugs or implement new features.
 \input crossrefenum.tex
 \ProvidesPackage{crossrefenum}[\crfnmDate{} v\crfnmVersion{} Enumeration of cross-references]
 \endinput
\ No newline at end of file
diff --git a/tex/t-crossrefenum.tex b/tex/t-crossrefenum.tex
index b516ab3..9629faf 100644
--- a/tex/t-crossrefenum.tex
+++ b/tex/t-crossrefenum.tex
@@ -9,6 +9,10 @@
 %D    copyright=Bastien Dumont,
 %D      license=GNU Public License v. 3.0 or higher]
 
+% This file cannot be loaded in main-test.tex for it would load the version of crossrefenum.tex
+% installed in the texmf tree.
+% As a consequence, it should not be changed to correct bugs or implement new features.
+
 \startmodule[crossrefenum]
 \unprotect