diff --git a/_locales/en/messages.json b/_locales/en/messages.json
index 08e8541f2f..b2823c7631 100644
--- a/_locales/en/messages.json
+++ b/_locales/en/messages.json
@@ -112,10 +112,26 @@
         "message": "Cycle Time:"
     },
 
+    "please_grant_usb_permissions": {
+        "message": "Please click on <strong>\"Request Optional Permissions\"</strong> button to grant application <strong style=\"color: red\">required</strong> <strong>USB</strong> access"
+    },
+    "usb_permissions_granted": {
+        "message": "Optional <strong>USB</strong> permissions <strong style=\"color: green\">granted</strong>"
+    },
+
     "eeprom_saved_ok": {
         "message": "EEPROM <span style=\"color: green\">saved</span>"
     },
 
+    "default_optional_permissions_head": {
+        "message": "Optional USB Permissions"
+    },
+    "default_optional_permissions_text": {
+        "message": "Due to addition of <strong>Naze32PRO</strong> to the supported hardware family, Configurator <strong style=\"color: red\">requires</strong> USB access to allow firmware flashing via DFU"
+    },
+    "default_request_optional_permissions": {
+        "message": "Request Optional Permissions"
+    },
     "defaultWelcomeText": {
         "message": "This application is a configuration utility for baseflight, a 32 bit fork of the popular open source RC flight control firmware project <a href=\"http://www.multiwii.org/\" title=\"www.multiwii.org\" target=\"_blank\">MultiWii</a>.<br /><br />Application supports hardware that run Baseflight <strong>exclusively</strong> (acro naze, naze, afromini)<br /><br /><strong>Official Resellers &amp; Backers</strong><br />&bull; <a href=\"http://www.abusemark.com/store/\" title=\"www.abusemark.com\" target=\"_blank\">AbuseMark</a> - International (Japan)<br />&bull; <a href=\"http://www.multirotorsuperstore.com/\" title=\"www.multirotorsuperstore.com\" target=\"_blank\">Multirotor Superstore</a> - International (United States)<br /><br />The firmware source code can be downloaded from <a href=\"https://github.com/multiwii/baseflight\" title=\"www.github.com\" target=\"_blank\">here</a><br />The newest binary firmware image is available <a href=\"https://github.com/multiwii/baseflight/blob/master/obj/baseflight.hex\" title=\"www.github.com\" target=\"_blank\">here</a><br />"
     },
diff --git a/js/gui.js b/js/gui.js
index 0933c3e6db..cdf00f0618 100644
--- a/js/gui.js
+++ b/js/gui.js
@@ -4,6 +4,7 @@ var GUI_control = function() {
     this.connected_to = false;
     this.active_tab;
     this.operating_system;
+    this.optional_usb_permissions = false; // controlled by usb permissions code
     this.interval_array = [];
     this.timeout_array = [];
 
diff --git a/js/stm32dfu.js b/js/stm32dfu.js
index dc4a73682f..97a1fafb01 100644
--- a/js/stm32dfu.js
+++ b/js/stm32dfu.js
@@ -53,12 +53,6 @@ var STM32DFU_protocol = function() {
         dfuUPLOAD_IDLE:         9, // The device is processing an upload operation. Expecting DFU_UPLOAD requests.
         dfuERROR:               10 // An error has occurred. Awaiting the DFU_CLRSTATUS request.
     };
-
-    this.usbDevices = {
-        F3DiscoveryDFU: {'vendorId': 1155, 'productId': 57105}
-    };
-
-    this.usbPermissions = {permissions: [{'usbDevices': [this.usbDevices.F3DiscoveryDFU]}]};
 };
 
 STM32DFU_protocol.prototype.openDevice = function(callback) {
diff --git a/js/usb.js b/js/usb.js
new file mode 100644
index 0000000000..1134658ae4
--- /dev/null
+++ b/js/usb.js
@@ -0,0 +1,32 @@
+var usbDevices = {
+    STM32DFU: {'vendorId': 1155, 'productId': 57105}
+};
+var usbPermissions = {permissions: [{'usbDevices': [usbDevices.STM32DFU]}]};
+
+function check_usb_permissions(callback) {
+    chrome.permissions.contains(usbPermissions, function(result) {
+        if (result) {
+            GUI.optional_usb_permissions = true;
+        } else {
+            console.log('Optional USB permissions: missing');
+            GUI.log(chrome.i18n.getMessage('please_grant_usb_permissions'));
+
+            // display optional usb permissions request box
+            $('div.optional_permissions').show();
+
+            // UI hooks
+            document.getElementById("requestOptionalPermissions").addEventListener('click', function() {
+                chrome.permissions.request(usbPermissions, function(result) {
+                    if (result) {
+                        GUI.log(chrome.i18n.getMessage('usb_permissions_granted'));
+                        $('div.optional_permissions').hide();
+
+                        GUI.optional_usb_permissions = true;
+                    }
+                });
+            });
+        }
+
+        if (callback) callback();
+    });
+}
\ No newline at end of file
diff --git a/main.html b/main.html
index 59373e691a..5be08ecebd 100644
--- a/main.html
+++ b/main.html
@@ -25,6 +25,7 @@
         <script type="text/javascript" src="./js/port_handler.js"></script>
         <script type="text/javascript" src="./js/port_usage.js"></script>
         <script type="text/javascript" src="./js/serial.js"></script>
+        <script type="text/javascript" src="./js/usb.js"></script>
         <script type="text/javascript" src="./js/gui.js"></script>
         <script type="text/javascript" src="./js/request_balancer.js"></script>
         <script type="text/javascript" src="./js/serial_backend.js"></script>
diff --git a/tabs/default.css b/tabs/default.css
index 0aea6ddb75..259ed23d62 100644
--- a/tabs/default.css
+++ b/tabs/default.css
@@ -8,6 +8,45 @@
 
     width: calc(40% - 10px);
 }
+.tab-default .optional_permissions {
+    display: none;
+
+    margin-bottom: 10px;
+
+    border: 1px solid silver;
+}
+    .tab-default .optional_permissions .title {
+        line-height: 20px;
+
+        text-align: center;
+        font-weight: bold;
+        color: white;
+
+        border-bottom: 1px solid silver;
+        background-color: #cd4c4c;
+    }
+    .tab-default .optional_permissions p {
+        padding: 5px;
+    }
+    .tab-default .optional_permissions a {
+        display: block;
+        float: left;
+
+        height: 28px;
+        line-height: 28px;
+
+        margin: 0 0 5px 5px;
+        padding: 0 15px 0 15px;
+
+        text-align: center;
+        font-weight: bold;
+
+        border: 1px solid silver;
+        background-color: #ececec;
+    }
+    .tab-default .optional_permissions a:hover {
+        background-color: #dedcdc;
+    }
     .welcome {
         margin-bottom: 10px;
 
diff --git a/tabs/default.html b/tabs/default.html
index 616dc8db4b..548425c275 100644
--- a/tabs/default.html
+++ b/tabs/default.html
@@ -1,5 +1,12 @@
 <div class="tab-default">
     <div class="left">
+        <div class="optional_permissions">
+            <div class="title" i18n="default_optional_permissions_head"></div>
+            <p i18n="default_optional_permissions_text">
+            </p>
+            <a id="requestOptionalPermissions" href="#" i18n="default_request_optional_permissions"></a>
+            <div class="clear-both"></div>
+        </div>
         <div class="welcome" i18n="defaultWelcomeText">
         </div>
         <div class="donate">
diff --git a/tabs/default.js b/tabs/default.js
index fbb2d1df20..0fb101fd02 100644
--- a/tabs/default.js
+++ b/tabs/default.js
@@ -2,6 +2,8 @@ function tab_initialize_default() {
     GUI.active_tab = 'default';
 
     $('#content').load("./tabs/default.html", function() {
+        check_usb_permissions(); // temporary enabled in dev branch, should be commented out untill DFU support goes live
+
         // translate to user-selected language
         localize();