diff --git a/Dockerfile b/Dockerfile
index fba49c2..d80614e 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -4,8 +4,9 @@ ENV BITCOIND_REV master
 
 ARG UBUNTU_MIRROR=mirror://mirrors.ubuntu.com/mirrors.txt
 
-RUN sed -i -e s#http://archive.ubuntu.com/ubuntu#${UBUNTU_MIRROR}#g \
-    -e s#http://security.ubuntu.com/ubuntu#${UBUNTU_MIRROR}#g \
+RUN sed -i \
+    -e s#http://archive.ubuntu.com/ubuntu/#${UBUNTU_MIRROR}#g \
+    -e s#http://security.ubuntu.com/ubuntu/#${UBUNTU_MIRROR}#g \
         /etc/apt/sources.list ; \
         cat /etc/apt/sources.list