escape a $ in a diagnostic

diff --git a/Makefile.maint b/Makefile.maint
index d0aad9b..cb94c39 100644 (file)
--- a/Makefile.maint
+++ b/Makefile.maint
@@ -278,7 +278,7 @@ strftime-check:
 # to emit a definition for each substituted variable.
 makefile-check:
        grep -E '@[A-Z_0-9]+@' `find . -name Makefile.am` \
-         && { echo 'Makefile.maint: use $(...), not @...@' 1>&2; exit 1; } || :
+         && { echo 'Makefile.maint: use $$(...), not @...@' 1>&2; exit 1; } || :
 
 news-date-check: NEWS
        today=`date +%Y-%m-%d`; \