diff --git a/Dockerfile b/Dockerfile
index b5b08f3..f10536f 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -3,7 +3,8 @@ MAINTAINER Tinpee <tinpee.dev@gmail.com>
 
 ADD . /src
 WORKDIR /src
-RUN pip install flask gunicorn
+RUN pip install --upgrade pip \
+    && pip install flask gunicorn
 
 COPY entrypoint.sh /
 RUN chmod +x /entrypoint.sh