diff --git a/Dockerfile b/Dockerfile
index 1b0f8d57..92009f5d 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -4,6 +4,7 @@ FROM debian:jessie
 MAINTAINER Project Jupyter <jupyter@googlegroups.com>
 
 ENV DEBIAN_FRONTEND=noninteractive
+ENV LANG=C.UTF-8
 RUN apt-get update \
   && apt-get install -y -q \
     build-essential \