diff --git a/configure.in b/configure.in
index 0db0923ffc..1f96c5a3f0 100644
--- a/configure.in
+++ b/configure.in
@@ -7884,7 +7884,7 @@ for subdir in `echo $SUBDIRS`; do
                 dnl assume that everything compiles for utils &c
                 dnl any that shouldn't be built can be added to
                 dnl DISABLED_UTILS, DISABLED_DEMOS
-                disabled_var=DISABLED_`echo $subdir | tr [[a-z]] [[A-Z]]`;
+                disabled_var=DISABLED_`echo $subdir | tr a-z A-Z`
                 eval "disabled=\$$disabled_var"
                 disabled=/`echo X $disabled | sed 's@ @/|/@g'`/
                 makefiles=`(cd $srcdir ; find $subdir -name Makefile.in) | $EGREP -v "$disabled"`