diff --git a/core/nginx/Dockerfile b/core/nginx/Dockerfile
index 839a1cc..5b0040a 100644
--- a/core/nginx/Dockerfile
+++ b/core/nginx/Dockerfile
@@ -1,6 +1,9 @@
-FROM alpine:3.7
+FROM alpine:3.8
 
 RUN apk add --no-cache nginx nginx-mod-mail python py-jinja2 certbot openssl
+# added to fix #522
+RUN apk add --no-cache py-requests-toolbelt py-pip
+RUN pip install "idna<2.7"
 
 COPY conf /conf
 COPY *.py /