diff --git a/run_tests.sh b/run_tests.sh
index 0fd7f4169..0b7f52a55 100755
--- a/run_tests.sh
+++ b/run_tests.sh
@@ -67,6 +67,10 @@ export NOSE_OPENSTACK_YELLOW=0.025
 export NOSE_OPENSTACK_SHOW_ELAPSED=1
 export NOSE_OPENSTACK_STDOUT=1
 
+export LANG=en_US.UTF-8
+export LANGUAGE=en_US:en
+export LC_ALL=C
+
 for arg in "$@"; do
   process_option $arg
 done
diff --git a/tox.ini b/tox.ini
index b95decf9e..4957ce39a 100644
--- a/tox.ini
+++ b/tox.ini
@@ -9,6 +9,10 @@ setenv = VIRTUAL_ENV={envdir}
          NOSE_OPENSTACK_YELLOW=0.025
          NOSE_OPENSTACK_SHOW_ELAPSED=1
          NOSE_OPENSTACK_STDOUT=1
+         LANG=en_US.UTF-8
+         LANGUAGE=en_US:en
+         LC_ALL=C
+
 deps = -r{toxinidir}/tools/pip-requires
        -r{toxinidir}/tools/test-requires
 commands = nosetests {posargs}