diff --git a/HISTORY.rst b/HISTORY.rst
index 7fd48653..f5e92b65 100644
--- a/HISTORY.rst
+++ b/HISTORY.rst
@@ -4,6 +4,17 @@ Release Notes
 PlatformIO 3.0
 --------------
 
+3.1.1 (2016-??-??)
+~~~~~~~~~~~~~~~~~~
+
+* Improved detecting of ARM mbed media disk for uploading
+
+-------
+
+* Development platform `ST STM32 <https://github.com/platformio/platform-ststm32>`__
+
+  + Added support for new boards: ST 32F769IDISCOVERY
+
 3.1.0 (2016-09-19)
 ~~~~~~~~~~~~~~~~~~
 
diff --git a/platformio/__init__.py b/platformio/__init__.py
index 476cae5d..9e4ad77e 100644
--- a/platformio/__init__.py
+++ b/platformio/__init__.py
@@ -14,7 +14,7 @@
 
 import sys
 
-VERSION = (3, 1, 0)
+VERSION = (3, 1, "1a1")
 __version__ = ".".join([str(s) for s in VERSION])
 
 __title__ = "platformio"
diff --git a/platformio/builder/tools/pioupload.py b/platformio/builder/tools/pioupload.py
index b3f528f6..d0c54451 100644
--- a/platformio/builder/tools/pioupload.py
+++ b/platformio/builder/tools/pioupload.py
@@ -87,10 +87,11 @@ def AutodetectUploadPort(*args, **kwargs):  # pylint: disable=unused-argument
     def _look_for_mbed_disk():
         msdlabels = ("mbed", "nucleo", "frdm", "microbit")
         for item in util.get_logicaldisks():
-            if (not item['name'] or
-                    not any([l in item['name'].lower() for l in msdlabels])):
-                continue
-            return item['disk']
+            if (item['name'] and
+                    any([l in item['name'].lower() for l in msdlabels])):
+                return item['disk']
+            if isfile(join(item['disk'], "mbed.html")):
+                return item['disk']
         return None
 
     def _look_for_serial_port():