diff --git a/.travis.yml b/.travis.yml
new file mode 100644
index 0000000..6747121
--- /dev/null
+++ b/.travis.yml
@@ -0,0 +1,13 @@
+# Travis CI Configuration File
+
+services:
+  - docker
+
+notifications:
+  email: false
+
+before_script:
+  - npm run build-node-modules
+
+script:
+  - npm run test
diff --git a/package.json b/package.json
index 856cdf8..752d1e1 100755
--- a/package.json
+++ b/package.json
@@ -16,6 +16,8 @@
   "scripts": {
     "build-node-modules": "rm -R node_modules ; docker run --rm -v `pwd`:/var/task lambci/lambda:build-nodejs10.x npm install",
     "test-file": "docker run --rm -e S3_BUCKET=hmn-uploads-eu -e S3_REGION=eu-west-1 -v `pwd`:/var/task lambci/lambda:nodejs10.x lambda-handler.handler '{\"path\":\"/'$npm_config_path'\", \"headers\":{}}'",
+    "test": "docker run --rm -v `pwd`:/var/task -it --entrypoint='node' lambci/lambda:nodejs10.x /var/task/test-filesize/index.js",
+    "update-test-fixtures": "docker run --rm -v `pwd`:/var/task -it --entrypoint='node' lambci/lambda:nodejs10.x /var/task/test-filesize/index.js --update-fixtures",
     "build-zip": "rm lambda.zip; zip -r --exclude='node_modules/aws-sdk/*' --exclude='node_modules/animated-gif-detector/test/*' lambda.zip ./node_modules/ index.js proxy-file.js lambda-handler.js",
     "upload-zip": "aws s3 --region=$npm_config_region cp ./lambda.zip s3://$npm_config_bucket/$npm_config_path",
     "update-function-code": "aws lambda update-function-code --region $npm_config_region --function-name $npm_config_function_name --zip-file fileb://`pwd`/lambda.zip"
diff --git a/test-filesize/fixtures.json b/test-filesize/fixtures.json
new file mode 100644
index 0000000..12813c2
--- /dev/null
+++ b/test-filesize/fixtures.json
@@ -0,0 +1,27 @@
+{
+    "briefing-copywriting.jpg-original.jpeg": 115390,
+    "briefing-copywriting.jpg-small.jpeg": 3092,
+    "briefing-copywriting.jpg-medium.jpeg": 9584,
+    "briefing-copywriting.jpg-large.jpeg": 29223,
+    "briefing-copywriting.jpg-webp.webp": 15660,
+    "hdr.jpg-original.jpeg": 149042,
+    "hdr.jpg-small.jpeg": 10589,
+    "hdr.jpg-medium.jpeg": 24100,
+    "hdr.jpg-large.jpeg": 87533,
+    "hdr.jpg-webp.webp": 82784,
+    "Website.png-original.png": 34589,
+    "Website.png-small.png": 3420,
+    "Website.png-medium.png": 13778,
+    "Website.png-large.png": 34589,
+    "Website.png-webp.webp": 20288,
+    "icons.png-original.png": 28026,
+    "icons.png-small.png": 3948,
+    "icons.png-medium.png": 11212,
+    "icons.png-large.png": 26372,
+    "icons.png-webp.webp": 24816,
+    "humans.png-original.png": 873684,
+    "humans.png-small.png": 9175,
+    "humans.png-medium.png": 56093,
+    "humans.png-large.png": 279635,
+    "humans.png-webp.webp": 141340
+}
diff --git a/test-filesize/index.js b/test-filesize/index.js
index 75b330f..eeae9f7 100644
--- a/test-filesize/index.js
+++ b/test-filesize/index.js
@@ -3,14 +3,16 @@ const Filesize = require('filesize');
 const tachyon = require('../index');
 const fs = require('fs');
 
-let images = fs.readdirSync('./images');
+let images = fs.readdirSync( __dirname + '/images' );
 
 const args = process.argv.slice(2);
 
-if ( args[0] ) {
+if ( args[0] && args[0].indexOf( '--' ) !== 0 ) {
 	images = images.filter( file => args[0] === file );
 }
 
+const saveFixtured = args.indexOf( '--update-fixtures' ) > -1;
+
 const table = new Table({
 	head: [
 		'Image',
@@ -24,6 +26,11 @@ const table = new Table({
 	colWidths: [30, 15, 20, 15, 15, 15, 20],
 });
 
+// Read in existing features for resizes, so we can detect if image resizing
+// has lead to a change in file size from previous runs.
+const oldFixtures = JSON.parse( fs.readFileSync( __dirname + '/fixtures.json' ) );
+const fixtures = {};
+
 async function test() {
 	await Promise.all(
 		images.map(async imageName => {
@@ -51,7 +58,9 @@ async function test() {
 
 			// Save each one to the file system for viewing.
 			Object.entries(resized).forEach(([size, image]) => {
-				fs.writeFile( `${__dirname}/output/${imageName}-${size}.${image.info.format}`, image.data, () => {});
+				const imageKey = `${imageName}-${size}.${image.info.format}`;
+				fixtures[ imageKey ] = image.data.length;
+				fs.writeFile( `${__dirname}/output/${imageKey}`, image.data, () => {});
 			});
 
 			table.push([
@@ -69,10 +78,36 @@ async function test() {
 					Math.floor(resized.webp.info.size / resized.large.info.size * 100) +
 					'%)',
 			]);
+
 		})
 	);
 
+	if ( saveFixtured ) {
+		fs.writeFileSync( __dirname + '/fixtures.json', JSON.stringify( fixtures, null, 4 ) );
+	}
+
 	console.log(table.toString());
+
+	let exitCode = 0;
+	for (const key in fixtures) {
+		if ( ! oldFixtures[ key ] ) {
+			exitCode = 1;
+			console.error( `${ key } not found in existing fixtures.` );
+		}
+		if ( fixtures[ key ] > oldFixtures[ key ] ) {
+			const diff = fixtures[ key ] / oldFixtures[ key ] * 100;
+			exitCode = 1;
+			console.error( `${ key } is larger than image in fixtures (${ fixtures[ key ] - oldFixtures[ key ] } bytes larger, ${ diff }%.)` );
+		}
+
+		if ( fixtures[ key ] < oldFixtures[ key ] ) {
+			const diff = oldFixtures[ key ] / fixtures[ key ] * 100;
+			console.log( `${ key } is smaller than image in fixtures (${ fixtures[ key ] - oldFixtures[ key ] } bytes smaller, ${ diff }%.)` );
+		}
+	}
+	// Exit the script if the fixtures have changed in a negative direction. This means
+	// TravisCI etc will detect the failure correctly.
+	process.exit(exitCode);
 }
 
 test();