diff --git a/api/1.0/api.js b/api/1.0/api.js
index 3d2d463..22481ac 100644
--- a/api/1.0/api.js
+++ b/api/1.0/api.js
@@ -168,7 +168,7 @@ Generator.prototype.generate = function(cb) {
   this.seedRNG();
 
   if (this.format === 'yaml') {
-    cb(YAML.stringify(json, 4), "yml");
+    cb(YAML.stringify(json, 4), "yaml");
   } else if (this.format === 'xml') {
     cb(js2xmlparser('user', json), "xml");
   } else if (this.format === 'prettyjson' || this.format === 'pretty') {
diff --git a/routes/api.js b/routes/api.js
index 6687986..29f8982 100644
--- a/routes/api.js
+++ b/routes/api.js
@@ -59,12 +59,15 @@ function genUser(req, res, version) {
       res.setHeader('Content-disposition', 'attachment; filename=download.' + ext);
       fs.writeFileSync(name, output, 'utf8');
     } else {
-
-      if (ext === 'json'){
+      if (ext === 'json') {
         res.setHeader('Content-Type', 'application/json');
-      }else if (ext === 'xml'){
+      } else if (ext === 'xml') {
         res.setHeader('Content-Type', 'text/xml');
-      }else{
+      } else if (ext === 'yaml') {
+        res.setHeader('Content-Type', 'text/x-yaml');
+      } else if (ext === 'csv') {
+        res.setHeader('Content-Type', 'text/csv');
+      } else {
         res.setHeader('Content-Type', 'text/plain');
       }
     }
diff --git a/spec/randomuserTests.js b/spec/randomuserTests.js
index 8765712..37808ad 100644
--- a/spec/randomuserTests.js
+++ b/spec/randomuserTests.js
@@ -376,6 +376,50 @@ describe('Randomuser.me', () => {
           } catch(e) {}
         });
       });
+
+      describe('MIME type testing', () => {
+        it('should return content type application/json when no format specified', (done) => {
+          request(server).get('/api').expect('Content-Type', /application\/json/)
+          .end((err, res) => {
+            if (!err) done();
+          });
+        });
+
+        it('should return content type application/json when JSON format specified', (done) => {
+          request(server).get('/api/?fmt=json').expect('Content-Type', /application\/json/)
+          .end((err, res) => {
+            if (!err) done();
+          });
+        });
+
+        it('should return content type application/json when pretty format specified', (done) => {
+          request(server).get('/api/?fmt=pretty').expect('Content-Type', /application\/json/)
+          .end((err, res) => {
+            if (!err) done();
+          });
+        });
+
+        it('should return content type text/xml when XML format specified', (done) => {
+          request(server).get('/api/?fmt=xml').expect('Content-Type', /text\/xml/)
+          .end((err, res) => {
+            if (!err) done();
+          });
+        });
+
+        it('should return content type text/x-yaml when YAML format specified', (done) => {
+          request(server).get('/api/?fmt=yaml').expect('Content-Type', /text\/x\-yaml/)
+          .end((err, res) => {
+            if (!err) done();
+          });
+        });
+
+        it('should return content type text/csv when CSV format specified', (done) => {
+          request(server).get('/api/?fmt=csv').expect('Content-Type', /text\/csv/)
+          .end((err, res) => {
+            if (!err) done();
+          });
+        });
+      });
     });
   });
 });