diff --git a/configure.ac b/configure.ac
index 45b11ae4c74fb2bd87ad43f51434540473abac56..824c41463953d3eca889be112011941706fabe77 100644
--- a/configure.ac
+++ b/configure.ac
@@ -115,7 +115,7 @@ gltools_include=
 LIBGLTOOLS_PRESENT=
 AC_MSG_CHECKING([for libgltools.a])
 AC_ARG_WITH(gltools,
-[  --with-gltools=PATH     specify the path of the gltools library],
+[  --with-gltools=PATH     specify the absolute path of the gltools library],
 [if test -f $withval/gltools-2-3/libgltools.a; then
 	AC_MSG_RESULT([Found libgltools.a in specified directory $withval/gltools-2-3.])
 	gltools_include="-I$withval/gltools-2-3"