--- acpica-unix-20140828/generate/unix/Makefile.config
+++ acpica-unix-20140828/generate/unix/Makefile.config
@@ -225,12 +225,12 @@
 #YACC=      byacc
 #YFLAGS +=
 #
-YACC=       bison
+YACC=       LC_ALL=C bison
 YFLAGS +=   -y
 
 MACROPROC=  m4
 MFLAGS=     -P -I$(ASL_COMPILER)
 
-LEX=        flex
+LEX=        LC_ALL=C flex
 LFLAGS +=   -i -s