diff --git a/.travis.yml b/.travis.yml
index 4f3a3bc7e..3fda78932 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,14 +1,21 @@
 language: node_js
 node_js:
-  - "4.2"
+  - "4"
 sudo: false
 before_install:
-  - export WAPPALYZER_ROOT=$TRAVIS_BUILD_DIR
-  - export WAPPALYZER_NODE_PATH=$TRAVIS_BUILD_DIR
-  - export PATH=$PATH:$TRAVIS_BUILD_DIR/bin
-install:
-  - npm install jsonlint jpm imagemin-cli svgo -g
-  - ln -s docker/node/package.json package.json && npm install
-  - mkdir phantomjs && curl -L https://bitbucket.org/ariya/phantomjs/downloads/phantomjs-1.9.8-linux-x86_64.tar.bz2 | tar xvjC phantomjs && ln -s $WAPPALYZER_ROOT/phantomjs/phantomjs-*-linux-x86_64/bin/phantomjs bin/phantomjs
-script: wappalyzer build
+ - export WAPPALYZER_ROOT=$TRAVIS_BUILD_DIR
+ - export WAPPALYZER_NODE_PATH=$TRAVIS_BUILD_DIR
+ - export PATH=$PATH:$TRAVIS_BUILD_DIR/bin
+ - ln -s docker/node/package.json package.json
 after_script: ls -l --block-size=kB build
+cache:
+  directories:
+    - node_modules
+env:
+  - CXX=g++-4.8
+addons:
+  apt:
+    sources:
+      - ubuntu-toolchain-r-test
+    packages:
+      - g++-4.8
diff --git a/bin/wappalyzer-build b/bin/wappalyzer-build
index 8eb689945..0d48405a1 100755
--- a/bin/wappalyzer-build
+++ b/bin/wappalyzer-build
@@ -7,21 +7,28 @@ then
 	exit 1
 fi
 
+if [ -z $WAPPALYZER_NODE_PATH ]
+then
+	echo "\$WAPPALYZER_NODE_PATH not set"
+
+	exit 1
+fi
+
 set -eu
 
 wappalyzer validate
 
 echo "Prettifying apps.json..."
 
-jsonlint -ist $'\t' $WAPPALYZER_ROOT/src/apps.json
+node $WAPPALYZER_NODE_PATH/node_modules/jsonlint/lib/cli.js -ist $'\t' $WAPPALYZER_ROOT/src/apps.json
 
 echo "Compressing PNG icons..."
 
-imagemin $WAPPALYZER_ROOT/src/icons $WAPPALYZER_ROOT/src/icons -o 7
+node $WAPPALYZER_NODE_PATH/node_modules/imagemin-cli/cli.js $WAPPALYZER_ROOT/src/icons $WAPPALYZER_ROOT/src/icons -o 7
 
 echo "Compressing SVG icons..."
 
-svgo -q -f $WAPPALYZER_ROOT/src/icons $WAPPALYZER_ROOT/src/icons
+node $WAPPALYZER_NODE_PATH/node_modules/svgo/bin/svgo -q -f $WAPPALYZER_ROOT/src/icons $WAPPALYZER_ROOT/src/icons
 
 wappalyzer links
 
@@ -34,7 +41,7 @@ echo "Building Firefox driver..."
 
 pushd $WAPPALYZER_ROOT/src/drivers/firefox > /dev/null
 
-jpm xpi && mv *.xpi $WAPPALYZER_ROOT/build/wappalyzer_firefox.xpi
+node $WAPPALYZER_NODE_PATH/node_modules/jpm/bin/jpm xpi && mv *.xpi $WAPPALYZER_ROOT/build/wappalyzer_firefox.xpi
 
 popd > /dev/null
 
diff --git a/bin/wappalyzer-validate b/bin/wappalyzer-validate
index a6e8c691e..d9d09a617 100755
--- a/bin/wappalyzer-validate
+++ b/bin/wappalyzer-validate
@@ -27,7 +27,7 @@ path="$path/src"
 
 echo "Validating apps.json..."
 
-jsonlint --quiet -V $WAPPALYZER_ROOT/schema.json $path/apps.json
+node $WAPPALYZER_NODE_PATH/node_modules/jsonlint/lib/cli.js --quiet -V $WAPPALYZER_ROOT/schema.json $path/apps.json
 
 echo "Validating regular expressions..."
 
diff --git a/bin/wappalyzer-validate-icons b/bin/wappalyzer-validate-icons
index 38a8cb2bf..3ec796ac6 100755
--- a/bin/wappalyzer-validate-icons
+++ b/bin/wappalyzer-validate-icons
@@ -31,7 +31,11 @@ for (app in json.apps) {
 			if (exists) {
         if (type === "PNG") {
           var buffer = fileType(readChunk.sync(path, 0, 262));
-          if (buffer.mime !== 'image/png') {
+          if (buffer === null) {
+            var err = new Error('Unknown mimetype or bad file for "' + app + '": src/icons/' + iconPath);
+            throw err;
+          }
+          else if (buffer.mime !== 'image/png') {
             var err = new Error('Incorrect mimetype "' + buffer.mime + '" when expected PNG for app "' + app + '": src/icons/' + iconPath);
             throw err;
           }
diff --git a/docker/Dockerfile b/docker/Dockerfile
index 857cf65a6..625b6bf14 100644
--- a/docker/Dockerfile
+++ b/docker/Dockerfile
@@ -32,7 +32,7 @@ RUN su wappalyzer -c "mkdir $WAPPALYZER_NODE_PATH"
 
 ADD node/package.json $WAPPALYZER_NODE_PATH/package.json
 
-RUN npm install jsonlint jpm imagemin-cli svgo -g && su wappalyzer -c "cd $WAPPALYZER_NODE_PATH && npm install"
+RUN su wappalyzer -c "cd $WAPPALYZER_NODE_PATH && npm i"
 
 
 # PhantomJS
diff --git a/docker/node/package.json b/docker/node/package.json
index 9855b7b74..b75954434 100644
--- a/docker/node/package.json
+++ b/docker/node/package.json
@@ -1,7 +1,26 @@
 {
+  "name": "wappalyzer-test",
+  "private": true,
+  "license": "GPLv3",
+  "bugs": {
+    "url": "https://github.com/AliasIO/Wappalyzer/issues"
+  },
+  "homepage": "https://github.com/AliasIO/Wappalyzer",
+  "description": "Build test for Wappalyzer",
+  "repository": "AliasIO/Wappalyzer",
+  "scripts": {
+    "test": "./bin/wappalyzer build"
+  },
   "devDependencies": {
-    "file-type": "3.3.*",
+    "file-type": "3.4.*",
 	"is-svg": "1.1.*",
-    "read-chunk": "1.0.*"
+    "read-chunk": "1.0.*",
+    "jsonlint": "*",
+    "jpm": "*",
+    "imagemin-cli": "*",
+    "svgo": "*"
+  },
+  "engines": {
+    "node": ">= 4"
   }
 }