diff --git a/1.6/Dockerfile b/1.6/Dockerfile
index 8d50e33..53e5270 100644
--- a/1.6/Dockerfile
+++ b/1.6/Dockerfile
@@ -1,7 +1,10 @@
 FROM buildpack-deps:jessie
 
 # gpg keys listed at https://github.com/iojs/io.js
-RUN gpg --keyserver pool.sks-keyservers.net --recv-keys 9554F04D7259F04124DE6B476D5A82AC7E37093B DD8F2338BAE7501E3DD5AC78C273792F7D83545D
+RUN gpg --keyserver pool.sks-keyservers.net --recv-keys \
+  9554F04D7259F04124DE6B476D5A82AC7E37093B \
+  DD8F2338BAE7501E3DD5AC78C273792F7D83545D \
+  FD3A5288F042B6850C66B31F09FE44734EB7990E
 
 ENV NPM_CONFIG_LOGLEVEL info
 ENV IOJS_VERSION 1.6.3
diff --git a/1.6/slim/Dockerfile b/1.6/slim/Dockerfile
index 2e66758..4eeafd6 100644
--- a/1.6/slim/Dockerfile
+++ b/1.6/slim/Dockerfile
@@ -1,7 +1,10 @@
 FROM buildpack-deps:jessie-curl
 
 # gpg keys listed at https://github.com/iojs/io.js
-RUN gpg --keyserver pool.sks-keyservers.net --recv-keys 9554F04D7259F04124DE6B476D5A82AC7E37093B DD8F2338BAE7501E3DD5AC78C273792F7D83545D
+RUN gpg --keyserver pool.sks-keyservers.net --recv-keys \
+  9554F04D7259F04124DE6B476D5A82AC7E37093B \
+  DD8F2338BAE7501E3DD5AC78C273792F7D83545D \
+  FD3A5288F042B6850C66B31F09FE44734EB7990E
 
 ENV NPM_CONFIG_LOGLEVEL info
 ENV IOJS_VERSION 1.6.3