diff --git a/m4/fptools_alex.m4 b/m4/fptools_alex.m4
index 527ee1e187b72a1a77a31de0434f871ac492176f..e5366e40f6b0cf1574da1d5001614ce10471b2b4 100644
--- a/m4/fptools_alex.m4
+++ b/m4/fptools_alex.m4
@@ -14,7 +14,7 @@ AC_SUBST(AlexCmd,$ALEX)
 AC_CACHE_CHECK([for version of alex], fptools_cv_alex_version,
 changequote(, )dnl
 [if test x"$AlexCmd" != x; then
-   fptools_cv_alex_version=`"$AlexCmd" -v |
+   fptools_cv_alex_version=`"$AlexCmd" -V |
               grep 'Alex [Vv]ersion' | sed -e 's/Alex [Vv]ersion \([0-9\.]*\).*/\1/g'` ;
 else
    fptools_cv_alex_version="";