diff --git a/Dockerfile b/Dockerfile
index 44cfe7c..4aa2738 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,9 +1,8 @@
 FROM prosody/prosody:0.11
 MAINTAINER Netz39 Administrators <admin@netz39.de>
 
-ENV DEBIAN_FRONTEND noninteractive
-RUN apt-get install -y --no-install-recommends --no-install-suggests \
-    mercurial
+RUN apt-get update \
+    && DEBIAN_FRONTEND=noninteractive apt-get install -y --no-install-recommends --no-install-suggests \
+        mercurial
 
-WORKDIR /usr/local/lib
-RUN hg clone https://hg.prosody.im/prosody-modules/ prosody-modules
+RUN hg clone https://hg.prosody.im/prosody-modules/ /usr/local/lib/prosody-modules