diff --git a/Dockerfile b/Dockerfile
index 92b149d..950153c 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -4,12 +4,12 @@ WORKDIR /usr/src/app
 COPY Gemfile /usr/src/app/
 COPY Gemfile.lock /usr/src/app/
 
-RUN apk --update add nodejs git ruby ruby-dev ruby-bundler less ruby-nokogiri build-base && \
+RUN apk --update add nodejs git zlib zlib-dev ruby ruby-dev ruby-bundler less build-base && \
     bundle install -j 4 && \
-    apk del build-base && rm -fr /usr/share/ri
+    apk del --purge build-base zlib zlib-dev && rm -fr /usr/share/ri
 
-ENV CSSLINT_SHA=0e7aeadd02f5babca5152993374043f9f736a116
-RUN npm install -g codeclimate/csslint.git#$CSSLINT_COMMIT
+ENV CSSLINT_SHA=87aa604a4cbc5125db979576f1b09b35980fcf08
+RUN npm install -g codeclimate/csslint.git#$CSSLINT_SHA
 
 RUN adduser -u 9000 -D app
 USER app
diff --git a/Gemfile.lock b/Gemfile.lock
index cd340ba..99ebd75 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -5,9 +5,11 @@ GEM
     diff-lcs (1.2.5)
     json (1.8.3)
     method_source (0.8.2)
-    mini_portile (0.6.2)
-    nokogiri (1.6.6.2)
-      mini_portile (~> 0.6.0)
+    mini_portile2 (2.1.0)
+    nokogiri (1.6.8)
+      mini_portile2 (~> 2.1.0)
+      pkg-config (~> 1.1.7)
+    pkg-config (1.1.7)
     pry (0.10.1)
       coderay (~> 1.1.0)
       method_source (~> 0.8.1)