diff --git a/package.json b/package.json
index 603bef6..09bae1a 100644
--- a/package.json
+++ b/package.json
@@ -20,10 +20,10 @@
     "svgfilter": "=0.3.1"
   },
   "devDependencies": {
-    "expect.js": "=0.2.0",
     "express": "=3.0.3",
     "mocha": "=1.7.3",
-    "request": "=2.12.0"
+    "request": "=2.12.0",
+    "unexpected": "=1.0.11"
   },
   "scripts": {
     "test": "mocha",
diff --git a/test/processImage.js b/test/processImage.js
index a40538d..56e6f52 100644
--- a/test/processImage.js
+++ b/test/processImage.js
@@ -2,7 +2,7 @@ var express = require('express'),
     Path = require('path'),
     request = require('request'),
     passError = require('passerror'),
-    expect = require('expect.js'),
+    expect = require('unexpected'),
     processImage = require('../lib/processImage'),
     Stream = require('stream'),
     gm = require('gm');
@@ -43,38 +43,38 @@ describe('test server', function () {
 
     it('should not mess with request for non-image file', function (done) {
         request(baseUrl + '/something.txt', passError(done, function (response, body) {
-            expect(body).to.equal("foo\n");
-            expect(response.headers['content-type']).to.equal('text/plain; charset=UTF-8');
+            expect(body, 'to equal', 'foo\n');
+            expect(response.headers['content-type'], 'to equal', 'text/plain; charset=UTF-8');
             done();
         }));
     });
 
     it('should not mess with request for image with no query string', function (done) {
         request({url: baseUrl + '/ancillaryChunks.png', encoding: null}, passError(done, function (response, body) {
-            expect(body.length).to.equal(152);
-            expect(response.headers['content-type']).to.equal('image/png');
+            expect(body.length, 'to equal', 152);
+            expect(response.headers['content-type'], 'to equal', 'image/png');
             done();
         }));
     });
 
     it('should not mess with request for image with an unsupported operation in the query string', function (done) {
         request({url: baseUrl + '/ancillaryChunks.png?foo=bar', encoding: null}, passError(done, function (response, body) {
-            expect(body.length).to.equal(152);
-            expect(response.headers['content-type']).to.equal('image/png');
+            expect(body.length, 'to equal', 152);
+            expect(response.headers['content-type'], 'to equal', 'image/png');
             done();
         }));
     });
 
     it('should run the image through pngcrush when the pngcrush CGI param is specified', function (done) {
         request({url: baseUrl + '/ancillaryChunks.png?pngcrush=-rem+alla', encoding: null}, passError(done, function (response, body) {
-            expect(response.statusCode).to.equal(200);
-            expect(response.headers['content-type']).to.equal('image/png');
-            expect(body.length).to.be.lessThan(152);
-            expect(body.length).to.be.greaterThan(0);
+            expect(response.statusCode, 'to equal', 200);
+            expect(response.headers['content-type'], 'to equal', 'image/png');
+            expect(body.length, 'to be less than', 152);
+            expect(body.length, 'to be greater than', 0);
             getImageMetadataFromBuffer(body, passError(done, function (metadata) {
-                expect(metadata.format).to.equal('PNG');
-                expect(metadata.size.width).to.equal(12);
-                expect(metadata.size.height).to.equal(5);
+                expect(metadata.format, 'to equal', 'PNG');
+                expect(metadata.size.width, 'to equal', 12);
+                expect(metadata.size.height, 'to equal', 5);
                 done();
             }));
         }));
@@ -82,14 +82,14 @@ describe('test server', function () {
 
     it('should run the image through pngquant when the pngquant CGI param is specified', function (done) {
         request({url: baseUrl + '/purplealpha24bit.png?pngquant', encoding: null}, passError(done, function (response, body) {
-            expect(response.statusCode).to.equal(200);
-            expect(response.headers['content-type']).to.equal('image/png');
-            expect(body.length).to.be.lessThan(8285);
-            expect(body.length).to.be.greaterThan(0);
+            expect(response.statusCode, 'to equal', 200);
+            expect(response.headers['content-type'], 'to equal', 'image/png');
+            expect(body.length, 'to be less than', 8285);
+            expect(body.length, 'to be greater than', 0);
             getImageMetadataFromBuffer(body, passError(done, function (metadata) {
-                expect(metadata.format).to.equal('PNG');
-                expect(metadata.size.width).to.equal(100);
-                expect(metadata.size.height).to.equal(100);
+                expect(metadata.format, 'to equal', 'PNG');
+                expect(metadata.size.width, 'to equal', 100);
+                expect(metadata.size.height, 'to equal', 100);
                 done();
             }));
         }));
@@ -97,15 +97,15 @@ describe('test server', function () {
 
     it('should run the image through jpegtran when the jpegtran CGI param is specified', function (done) {
         request({url: baseUrl + '/turtle.jpg?jpegtran=-grayscale,-flip,horizontal', encoding: null}, passError(done, function (response, body) {
-            expect(response.statusCode).to.equal(200);
-            expect(response.headers['content-type']).to.equal('image/jpeg');
-            expect(body.length).to.be.lessThan(105836);
-            expect(body.length).to.be.greaterThan(0);
+            expect(response.statusCode, 'to equal', 200);
+            expect(response.headers['content-type'], 'to equal', 'image/jpeg');
+            expect(body.length, 'to be less than', 105836);
+            expect(body.length, 'to be greater than', 0);
             getImageMetadataFromBuffer(body, passError(done, function (metadata) {
-                expect(metadata.format).to.equal('JPEG');
-                expect(metadata.size.width).to.equal(481);
-                expect(metadata.size.height).to.equal(424);
-                expect(metadata['Channel Depths'].Gray).to.equal('8 bits');
+                expect(metadata.format, 'to equal', 'JPEG');
+                expect(metadata.size.width, 'to equal', 481);
+                expect(metadata.size.height, 'to equal', 424);
+                expect(metadata['Channel Depths'].Gray, 'to equal', '8 bits');
                 done();
             }));
         }));
@@ -113,15 +113,15 @@ describe('test server', function () {
 
     it('should run the image through graphicsmagick when methods exposed by the gm module are added as CGI params', function (done) {
         request({url: baseUrl + '/turtle.jpg?resize=340,300', encoding: null}, passError(done, function (response, body) {
-            expect(response.statusCode).to.equal(200);
-            expect(response.headers['content-type']).to.equal('image/jpeg');
-            expect(body.slice(0, 10).toString()).to.equal(new Buffer([0xff, 0xd8, 0xff, 0xe0, 0x00, 0x10, 0x4a, 0x46, 0x49, 0x46]).toString());
-            expect(body.length).to.be.lessThan(105836);
-            expect(body.length).to.be.greaterThan(0);
+            expect(response.statusCode, 'to equal', 200);
+            expect(response.headers['content-type'], 'to equal', 'image/jpeg');
+            expect(body.slice(0, 10).toString(), 'to equal', new Buffer([0xff, 0xd8, 0xff, 0xe0, 0x00, 0x10, 0x4a, 0x46, 0x49, 0x46]).toString());
+            expect(body.length, 'to be less than', 105836);
+            expect(body.length, 'to be greater than', 0);
             getImageMetadataFromBuffer(body, passError(done, function (metadata) {
-                expect(metadata.format).to.equal('JPEG');
-                expect(metadata.size.width).to.equal(340);
-                expect(metadata.size.height).to.equal(300);
+                expect(metadata.format, 'to equal', 'JPEG');
+                expect(metadata.size.width, 'to equal', 340);
+                expect(metadata.size.height, 'to equal', 300);
                 done();
             }));
         }));
@@ -129,14 +129,14 @@ describe('test server', function () {
 
     it('should run the image through svgfilter when the svgfilter parameter is specified', function (done) {
         request({url: baseUrl + '/dialog-information.svg?svgfilter=--runScript=addBogusElement.js,--bogusElementId=theBogusElementId'}, passError(done, function (response, svgText) {
-            expect(response.statusCode).to.equal(200);
-            expect(response.headers['content-type']).to.equal('image/svg+xml');
-            expect(response.headers.etag).to.be.ok();
-            // expect(response.headers.etag).to.match(/^"\d+-\d+-697ebc4fd42e6b09794a5d60968435a7-processimage"$/);
-            expect(svgText).to.match(/<svg/);
-            expect(svgText).to.match(/id="theBogusElementId"/);
+            expect(response.statusCode, 'to equal', 200);
+            expect(response.headers['content-type'], 'to equal', 'image/svg+xml');
+            expect(response.headers.etag, 'to be ok');
+            // expect(response.headers.etag, 'to match', /^"\d+-\d+-697ebc4fd42e6b09794a5d60968435a7-processimage"$/);
+            expect(svgText, 'to match', /<svg/);
+            expect(svgText, 'to match', /id="theBogusElementId"/);
             request({url: baseUrl + '/dialog-information.svg?svgfilter=--runScript=addBogusElement.js,--bogusElementId=theBogusElementId', headers: {'if-none-match': response.headers.etag}}, passError(done, function (response) {
-                expect(response.statusCode).to.equal(304);
+                expect(response.statusCode, 'to equal', 304);
                 done();
             }));
         }));
@@ -144,14 +144,14 @@ describe('test server', function () {
 
     it('should run the image through multiple filters when multiple CGI params are specified', function (done) {
         request({url: baseUrl + '/purplealpha24bit.png?resize=800,800&pngquant=8&pngcrush=-rem,gAMA', encoding: null}, passError(done, function (response, body) {
-            expect(response.statusCode).to.equal(200);
-            expect(response.headers['content-type']).to.equal('image/png');
-            expect(body.length).to.be.greaterThan(0);
-            expect(body.toString('ascii')).not.to.match(/gAMA/);
+            expect(response.statusCode, 'to equal', 200);
+            expect(response.headers['content-type'], 'to equal', 'image/png');
+            expect(body.length, 'to be greater than', 0);
+            expect(body.toString('ascii'), 'not to match', /gAMA/);
             getImageMetadataFromBuffer(body, passError(done, function (metadata) {
-                expect(metadata.format).to.equal('PNG');
-                expect(metadata.size.width).to.equal(800);
-                expect(metadata.size.height).to.equal(800);
+                expect(metadata.format, 'to equal', 'PNG');
+                expect(metadata.size.width, 'to equal', 800);
+                expect(metadata.size.height, 'to equal', 800);
                 done();
             }));
         }));
@@ -159,17 +159,17 @@ describe('test server', function () {
 
     it('should serve a converted image with the correct Content-Type', function (done) {
         request({url: baseUrl + '/purplealpha24bit.png?setFormat=jpg', encoding: null}, passError(done, function (response, body) {
-            expect(response.statusCode).to.equal(200);
-            expect(response.headers['content-type']).to.equal('image/jpeg');
-            expect(body.length).to.be.greaterThan(0);
-            expect(body.toString('ascii')).not.to.match(/gAMA/);
+            expect(response.statusCode, 'to equal', 200);
+            expect(response.headers['content-type'], 'to equal', 'image/jpeg');
+            expect(body.length, 'to be greater than', 0);
+            expect(body.toString('ascii'), 'not to match', /gAMA/);
             getImageMetadataFromBuffer(body, passError(done, function (metadata) {
-                expect(metadata.format).to.equal('JPEG');
-                expect(metadata.size.width).to.equal(100);
-                expect(metadata.size.height).to.equal(100);
+                expect(metadata.format, 'to equal', 'JPEG');
+                expect(metadata.size.width, 'to equal', 100);
+                expect(metadata.size.height, 'to equal', 100);
                 var etag = response.headers.etag;
-                expect(typeof etag).to.equal('string');
-                expect(etag).to.match(/-processimage/);
+                expect(typeof etag, 'to equal', 'string');
+                expect(etag, 'to match', /-processimage/);
                 request({
                     url: baseUrl + '/purplealpha24bit.png?setFormat=jpg',
                     encoding: null,
@@ -177,7 +177,7 @@ describe('test server', function () {
                         'if-none-match': etag
                     }
                 }, passError(done, function (response2, body2) {
-                    expect(response2.statusCode).to.equal(304);
+                    expect(response2.statusCode, 'to equal', 304);
                     done();
                 }));
             }));
@@ -186,14 +186,14 @@ describe('test server', function () {
 
     it('should serve an error response if an invalid image is processed with GraphicsMagick', function (done) {
         request({url: baseUrl + '/invalidImage.png?setFormat=jpg', encoding: null}, passError(done, function (response, body) {
-            expect(response.statusCode).to.be.greaterThan(399);
+            expect(response.statusCode, 'to be greater than or equal to', 400);
             done();
         }));
     });
 
     it('should serve an error response if an invalid image is processed with pngquant', function (done) {
         request({url: baseUrl + '/invalidImage.png?pngquant', encoding: null}, passError(done, function (response, body) {
-            expect(response.statusCode).to.be.greaterThan(399);
+            expect(response.statusCode, 'to be greater than or equal to', 400);
             done();
         }));
     });