diff --git a/tests/backslash-s-and-repetition-operators b/tests/backslash-s-and-repetition-operators
index 562646d..b1267f8 100755
--- a/tests/backslash-s-and-repetition-operators
+++ b/tests/backslash-s-and-repetition-operators
@@ -9,6 +9,11 @@

 . "${srcdir=.}/init.sh"; path_prepend_ ../src

+require_en_utf8_locale_
+
+LC_ALL=en_US.UTF-8
+export LC_ALL
+
 printf ' \n' > in || framework_failure_

 fail=0