diff --git a/configuration/configure.ac b/configuration/configure.ac
index e5c7d92..7320736 100644
--- a/configuration/configure.ac
+++ b/configuration/configure.ac
@@ -93,7 +93,7 @@
 dnl
 AC_PROG_SED
 AC_PATH_PROG(CUT, cut)
-AC_PROG_PERL_VERSION(5.6.0)
+AX_PROG_PERL_VERSION(5.6.0)
 AC_PATH_PROG(DATE, date)
 AC_PATH_PROG(EXPR, expr)
 AC_PATH_PROG(BASENAME, basename)
@@ -101,12 +101,11 @@
 AC_PATH_PROG(UNZIP, unzip)
 AC_PATH_PROG(GIT, git)
 AC_PATH_PROG(LOCKFILE, lockfile)
-AC_PATH_PROG(TR, tr)
 
 dnl Java stuff.
-AC_PROG_JAVA
-dnl AC_CHECK_CLASS([org.apache.xml.resolver.apps.resolver])
-dnl AC_CHECK_CLASS([net.sf.saxon.Transform])
+AX_PROG_JAVA
+dnl AX_CHECK_CLASS([org.apache.xml.resolver.apps.resolver])
+dnl AX_CHECK_CLASS([net.sf.saxon.Transform])
 
 dnl We make heavy use of features specific to GNU make.
 AC_CACHE_CHECK([for GNU make], [ac_cv_path_MAKE],