diff --git a/configure b/configure
index 14ef738..dd01911 100755
--- a/configure
+++ b/configure
@@ -3052,12 +3052,12 @@
   echo "CONFIG_LIBCAP=y" >> $config_host_mak
 fi
 for card in $audio_card_list; do
-    def=CONFIG_`echo $card | tr '[:lower:]' '[:upper:]'`
+    def=CONFIG_`echo $card | LC_ALL=C tr '[a-z]' '[A-Z]'`
     echo "$def=y" >> $config_host_mak
 done
 echo "CONFIG_AUDIO_DRIVERS=$audio_drv_list" >> $config_host_mak
 for drv in $audio_drv_list; do
-    def=CONFIG_`echo $drv | tr '[:lower:]' '[:upper:]'`
+    def=CONFIG_`echo $drv | LC_ALL=C tr '[a-z]' '[A-Z]'`
     echo "$def=y" >> $config_host_mak
     if test "$drv" = "fmod"; then
         echo "FMOD_CFLAGS=-I$fmod_inc" >> $config_host_mak
@@ -3618,7 +3618,7 @@
 echo "TARGET_LONG_ALIGNMENT=$target_long_alignment" >> $config_target_mak
 echo "TARGET_LLONG_ALIGNMENT=$target_llong_alignment" >> $config_target_mak
 echo "TARGET_ARCH=$TARGET_ARCH" >> $config_target_mak
-target_arch_name="`echo $TARGET_ARCH | tr '[:lower:]' '[:upper:]'`"
+target_arch_name="`echo $TARGET_ARCH | LC_ALL=C tr '[a-z]' '[A-Z]'`"
 echo "TARGET_$target_arch_name=y" >> $config_target_mak
 echo "TARGET_ARCH2=$target_arch2" >> $config_target_mak
 # TARGET_BASE_ARCH needs to be defined after TARGET_ARCH