diff --git a/Dockerfile b/Dockerfile
index 9b61160..2771720 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -7,7 +7,7 @@ RUN apk add --update --no-cache python3 python3-dev git build-base freetype-dev
 	if [ ! -e /usr/bin/pip ]; then ln -f /usr/bin/pip3 /usr/bin/pip ; fi
 
 RUN pip install --upgrade pip
-RUN pip install geopy gpxpy matplotlib numpy pandas
+RUN pip install cython geopy gpxpy matplotlib numpy pandas
 
 RUN git clone https://git.blackfinn.de/python/bicycle-statistics.git
 RUN cd bicycle-statistics && python setup.py install