diff --git a/lib/index.js b/lib/index.js
index ddd33e4..2c9426a 100644
--- a/lib/index.js
+++ b/lib/index.js
@@ -7,10 +7,14 @@ import EventEmitter from 'events';
 import { basename, resolve } from 'path';
 import { stat, readFile } from 'fs-promise';
 import resumer from 'resumer';
+import splitArray from 'split-array';
 
 // limit of size of files to find
 const ONEMB = bytes('1mb');
 
+// how many concurrent HTTP/2 stream uploads
+const MAX_CONCURRENT = 10;
+
 export default class Now extends EventEmitter {
   constructor (token, { forceNew = false, debug = false }) {
     super();
@@ -100,37 +104,49 @@ export default class Now extends EventEmitter {
   }
 
   upload () {
-    Promise.all(this._missing.map((sha) => retry(async (bail) => {
-      const file = this._files.get(sha);
-      const { data, name } = file;
+    const parts = splitArray(this._missing, MAX_CONCURRENT);
 
-      if (this._debug) console.time(`> [debug] /sync ${name}`);
+    if (this._debug) {
+      console.log('> [debug] Will upload ' +
+        `${this._missing.length} files in ${parts.length} ` +
+        `steps of ${MAX_CONCURRENT} uploads.`);
+    }
 
-      const stream = resumer().queue(data).end();
-      const res = await this._fetch('/sync', {
-        method: 'POST',
-        headers: {
-          'Content-Type': 'application/octet-stream',
-          'Content-Length': data.length,
-          'x-now-deployment-id': this._id,
-          'x-now-sha': sha,
-          'x-now-file': toRelative(name, this._path),
-          'x-now-size': data.length
-        },
-        body: stream
-      });
-      if (this._debug) console.timeEnd(`> [debug] /sync ${name}`);
+    const uploadChunk = () => {
+      Promise.all(parts.shift().map((sha) => retry(async (bail) => {
+        const file = this._files.get(sha);
+        const { data, name } = file;
+
+        if (this._debug) console.time(`> [debug] /sync ${name}`);
+
+        const stream = resumer().queue(data).end();
+        const res = await this._fetch('/sync', {
+          method: 'POST',
+          headers: {
+            'Content-Type': 'application/octet-stream',
+            'Content-Length': data.length,
+            'x-now-deployment-id': this._id,
+            'x-now-sha': sha,
+            'x-now-file': toRelative(name, this._path),
+            'x-now-size': data.length
+          },
+          body: stream
+        });
+        if (this._debug) console.timeEnd(`> [debug] /sync ${name}`);
+
+        // no retry on 403
+        if (403 === res.status) {
+          if (this._debug) console.log('> [debug] bailing on creating due to 403');
+          return bail(responseError(res));
+        }
 
-      // no retry on 403
-      if (403 === res.status) {
-        if (this._debug) console.log('> [debug] bailing on creating due to 403');
-        return bail(responseError(res));
-      }
+        this.emit('upload', file);
+      }, { retries: 5, randomize: true, onRetry: this._onRetry })))
+      .then(() => parts.length ? uploadChunk() : this.emit('complete'))
+      .catch((err) => this.emit('error', err));
+    };
 
-      this.emit('upload', file);
-    }, { retries: 5, randomize: true, onRetry: this._onRetry })))
-    .then(() => this.emit('complete'))
-    .catch((err) => this.emit('error', err));
+    uploadChunk();
   }
 
   _onRetry (err) {
diff --git a/package.json b/package.json
index 23e5da1..aa74f8f 100644
--- a/package.json
+++ b/package.json
@@ -25,7 +25,8 @@
     "progress": "1.1.8",
     "resumer": "0.0.0",
     "retry": "0.9.0",
-    "spdy": "3.2.3"
+    "spdy": "3.2.3",
+    "split-array": "1.0.1"
   },
   "devDependencies": {
     "alpha-sort": "1.0.2",