diff --git a/lib/clients/transports/request.js b/lib/clients/transports/request.js
index 5f42a41cc..677245b19 100644
--- a/lib/clients/transports/request.js
+++ b/lib/clients/transports/request.js
@@ -30,6 +30,18 @@ var getRequestTransportArgs = function getReqestTransportArgs(args) {
 
   if (has(args.data, 'file')) {
     transportArgs.formData = args.data;
+
+    // Buffers are sometimes not handled well by the underlying form-data package. Adding extra
+    // metadata can resolve this.
+    // see: https://github.com/slackapi/node-slack-sdk/issues/307#issuecomment-289231737
+    if (Buffer.isBuffer(transportArgs.formData.file) && has(args.data, 'filename')) {
+      transportArgs.formData.file = {
+        value: transportArgs.formData.file,
+        options: {
+          filename: args.data.filename
+        }
+      };
+    }
   } else {
     transportArgs.form = args.data;
   }
diff --git a/package.json b/package.json
index fc3a4a38a..dd079f206 100644
--- a/package.json
+++ b/package.json
@@ -36,6 +36,7 @@
     "ws": "^1.0.1"
   },
   "devDependencies": {
+    "busboy": "^0.2.14",
     "chai": "^3.5.0",
     "codecov": "^1.0.1",
     "eslint": "^2.2.0",
@@ -44,7 +45,7 @@
     "jsdoc-to-markdown": "^1.3.7",
     "mocha": "^3.4.1",
     "mocha-lcov-reporter": "^1.0.0",
-    "nock": "^7.2.2",
+    "nock": "^9.1.5",
     "sinon": "^1.17.1"
   },
   "engines": {
diff --git a/test/clients/web/client.js b/test/clients/web/client.js
index d8d4d9713..730fcf2a6 100644
--- a/test/clients/web/client.js
+++ b/test/clients/web/client.js
@@ -4,6 +4,7 @@ var path = require('path');
 var lodash = require('lodash');
 var nock = require('nock');
 var sinon = require('sinon');
+var Busboy = require('busboy');
 var pkginfo = require('pkginfo')(module, 'version', 'repository'); // eslint-disable-line no-unused-vars
 
 var WebAPIClient = require('../../../lib/clients/web/client');
@@ -99,7 +100,6 @@ describe('Web API Client', function () {
       expect(client.transport.args[0][0].data.body).to.equal('{"test": 10}');
       expect(client.transport.args[1][0].data.body).to.equal('{"test": 20}');
       expect(client.transport.args.length).to.equal(2);
-
     });
     done();
   });
@@ -110,7 +110,7 @@ describe('Web API Client', function () {
     client._makeAPICall('test', { test: 'test' }, null, null);
   });
 
-  it('should accept overriding of request options', function () {
+  it('should accept overriding of request options', function (done) {
 
     // Add Basic Auth
 
@@ -137,10 +137,63 @@ describe('Web API Client', function () {
 
     client._makeAPICall('test', {}, null, function (e, results) {
       expect(results.test).to.equal('test');
+      done();
     });
 
   });
 
+  it('should add metadata to raw Buffers for files.upload', function (done) {
+    var imageBuffer = fs.readFileSync(path.resolve('test', 'fixtures', 'train.jpg'));
+    var client = new WebAPIClient('test-token', { retryConfig: { retries: 0 } });
+
+    nock('https://slack.com/api')
+      .post('/files.upload')
+      .reply(function (uri, requestBody, cb) {
+        var busboy = new Busboy({ headers: this.req.headers });
+        var fileFound = false; // eslint-disable-line no-unused-vars
+        var filenameFound = false; // eslint-disable-line no-unused-vars
+        var errorFound = undefined;
+        var bodyBuffer;
+        busboy.on('file', function (fieldname, file, filename) {
+          fileFound = (fieldname === 'file' && filename === 'train.jpg');
+          file.resume();
+        });
+        busboy.on('field', function (fieldname, val) {
+          filenameFound = (fieldname === 'filename' && val === 'train.jpg');
+        });
+        busboy.on('error', function (error) {
+          errorFound = error;
+        });
+        busboy.on('finish', function () {
+          if (errorFound) {
+            cb(errorFound);
+          } else {
+            cb(null, [200, '{ "ok": true, "test": "passed" }']);
+          }
+        });
+        if (requestBody) {
+          if (lodash.isFunction(Buffer.from)) {
+            bodyBuffer = Buffer.from(requestBody, 'hex');
+          } else {
+            bodyBuffer = new Buffer(requestBody, 'hex');
+          }
+          busboy.end(bodyBuffer);
+        } else {
+          cb(null, [500, '{ "ok": false, "test": "failed" }']);
+        }
+      });
+
+    client._makeAPICall('files.upload',
+      { filename: 'train.jpg' },
+      { file: imageBuffer },
+      function (error, results) {
+        expect(error).to.not.be.an('error');
+        expect(results.test).to.equal('passed');
+        done();
+      }
+    );
+  });
+
   describe('it should retry failed or rate-limited requests', function () {
 
     var attemptAPICall = function (done) {
diff --git a/test/fixtures/train.jpg b/test/fixtures/train.jpg
new file mode 100644
index 000000000..849941d81
Binary files /dev/null and b/test/fixtures/train.jpg differ