diff --git a/testsuite/config/unix.exp b/testsuite/config/unix.exp
index 508fcd85..9092b9d4 100644
--- a/testsuite/config/unix.exp
+++ b/testsuite/config/unix.exp
@@ -1,4 +1,5 @@
 
+set env(LC_ALL) "C"
 regexp "(.*\/)testsuite" $objdir objdir topdir
 
 # These are the same as include/c.h