diff --git a/applets/busybox.sh b/applets/busybox.sh
index 6c91e539b..547aca477 100755
--- a/applets/busybox.sh
+++ b/applets/busybox.sh
@@ -3,7 +3,7 @@
 RAW=` \
     gcc -E -dM ${1:-Config.h} | \
     sed -n -e '/^.*BB_FEATURE.*$/d;s/^#define.*\<BB_\(.*\)\>/\1.c/gp;' \
-    | tr '[:upper:]' '[:lower:]' | sort
+    | tr A-Z a-z | sort
 `
 test "${RAW}" != "" ||  exit
 cd ${2:-.}
diff --git a/busybox.sh b/busybox.sh
index 6c91e539b..547aca477 100755
--- a/busybox.sh
+++ b/busybox.sh
@@ -3,7 +3,7 @@
 RAW=` \
     gcc -E -dM ${1:-Config.h} | \
     sed -n -e '/^.*BB_FEATURE.*$/d;s/^#define.*\<BB_\(.*\)\>/\1.c/gp;' \
-    | tr '[:upper:]' '[:lower:]' | sort
+    | tr A-Z a-z | sort
 `
 test "${RAW}" != "" ||  exit
 cd ${2:-.}