diff --git a/docker/ews/Dockerfile b/docker/ews/Dockerfile
index f21062f3..7626b7b0 100644
--- a/docker/ews/Dockerfile
+++ b/docker/ews/Dockerfile
@@ -7,6 +7,7 @@ ADD dist/ /root/dist/
 RUN apk -U --no-cache add \
             build-base \
             git \
+            libffi-dev \
             libssl1.0 \
             openssl-dev \
             python-dev \