diff --git a/HISTORY.rst b/HISTORY.rst
index d27a2a72..28e6f71e 100644
--- a/HISTORY.rst
+++ b/HISTORY.rst
@@ -5,6 +5,7 @@ Release History
 ---------
 
 * Fixed bug with order for includes in conversation from INO/PDE to CPP
+* Automatic detection of port on upload (`issue #15 <https://github.com/ivankravets/platformio/issues/15>`_)
 
 
 0.7.0 (2014-09-24)
diff --git a/platformio/builder/scripts/atmelavr.py b/platformio/builder/scripts/atmelavr.py
index dcaed8f6..5df536fa 100644
--- a/platformio/builder/scripts/atmelavr.py
+++ b/platformio/builder/scripts/atmelavr.py
@@ -11,7 +11,7 @@ from time import sleep
 from SCons.Script import (AlwaysBuild, Builder, COMMAND_LINE_TARGETS, Default,
                           DefaultEnvironment, Exit)
 
-from platformio.util import reset_serialport
+from platformio.util import get_serialports, reset_serialport
 
 env = DefaultEnvironment()
 
@@ -164,9 +164,19 @@ AlwaysBuild(uploadeep)
 
 is_uptarget = (set(["upload", "uploadlazy", "uploadeep"]) &
                set(COMMAND_LINE_TARGETS))
-if is_uptarget and not env.subst("$UPLOAD_PORT"):
-    Exit("Please specify environment 'upload_port' or use global "
-         "--upload-port option.")
+
+if is_uptarget:
+    # try autodetect upload port
+    if "UPLOAD_PORT" not in env:
+        for item in get_serialports():
+            if "VID:PID" in item['hwid']:
+                print ("Auto-detected UPLOAD_PORT: %s" % item['port'])
+                env['UPLOAD_PORT'] = item['port']
+                break
+
+    if "UPLOAD_PORT" not in env:
+        Exit("Please specify environment 'upload_port' or use global "
+             "--upload-port option.")
 
 #
 # Setup default targets