diff --git a/docker/bionic/Dockerfile b/docker/bionic/Dockerfile
index 54235b3..997af31 100644
--- a/docker/bionic/Dockerfile
+++ b/docker/bionic/Dockerfile
@@ -76,4 +76,8 @@ COPY entrypoint.sh /entrypoint.sh
 
 USER buildbot
 
+ENV LANG en_US.UTF-8
+ENV LANGUAGE en_US:en
+ENV LC_ALL en_US.UTF-8
+
 ENTRYPOINT /entrypoint.sh "$BUILDMASTER" "$WORKERNAME" "$WORKERPASS"