diff --git a/tests/roles/ibus-desktop-testing-role/tasks/main.yml b/tests/roles/ibus-desktop-testing-role/tasks/main.yml
index 72fac0a..f1d957e 100644
--- a/tests/roles/ibus-desktop-testing-role/tasks/main.yml
+++ b/tests/roles/ibus-desktop-testing-role/tasks/main.yml
@@ -58,10 +58,13 @@
     ANSIBLE: 1
     TMPDIR: '{{ remote_artifacts }}'
     G_MESSAGES_DEBUG: 'all'
+    LANG: 'C.UTF-8'
   block:
   - name: Execute IBus tests
     shell: |
       set -e
+      # Delete LC_CTYPE=C.UTF-8
+      export -n LC_CTYPE
       status="FAIL: frame"
       ibus-desktop-testing-runner \
           --no-graphics \