diff --git a/platformio/__init__.py b/platformio/__init__.py
index e6127e13..31611539 100644
--- a/platformio/__init__.py
+++ b/platformio/__init__.py
@@ -14,7 +14,7 @@
 
 import sys
 
-VERSION = (2, 9, 2)
+VERSION = (2, 9, "3.dev0")
 __version__ = ".".join([str(s) for s in VERSION])
 
 __title__ = "platformio"
diff --git a/platformio/builder/scripts/atmelavr.py b/platformio/builder/scripts/atmelavr.py
index 26370f22..a4b53263 100644
--- a/platformio/builder/scripts/atmelavr.py
+++ b/platformio/builder/scripts/atmelavr.py
@@ -22,6 +22,8 @@ from time import sleep
 from SCons.Script import (COMMAND_LINE_TARGETS, AlwaysBuild, Default,
                           DefaultEnvironment, SConscript)
 
+from platformio.util import get_serialports
+
 
 def BeforeUpload(target, source, env):  # pylint: disable=W0613,W0621
 
@@ -63,11 +65,13 @@ def BeforeUpload(target, source, env):  # pylint: disable=W0613,W0621
         if not upload_options.get("disable_flushing", False):
             env.FlushSerialBuffer("$UPLOAD_PORT")
 
+        before_ports = [i['port'] for i in get_serialports(use_grep=True)]
+
         if upload_options.get("use_1200bps_touch", False):
             env.TouchSerialPort("$UPLOAD_PORT", 1200)
 
         if upload_options.get("wait_for_upload_port", False):
-            env.Replace(UPLOAD_PORT=env.WaitForNewSerialPort())
+            env.Replace(UPLOAD_PORT=env.WaitForNewSerialPort(before_ports))
 
 
 env = DefaultEnvironment()
diff --git a/platformio/builder/scripts/atmelsam.py b/platformio/builder/scripts/atmelsam.py
index 7cf50a31..a78febf0 100644
--- a/platformio/builder/scripts/atmelsam.py
+++ b/platformio/builder/scripts/atmelsam.py
@@ -21,6 +21,8 @@ from os.path import basename, join
 from SCons.Script import (COMMAND_LINE_TARGETS, AlwaysBuild, Default,
                           DefaultEnvironment, SConscript)
 
+from platformio.util import get_serialports
+
 
 def BeforeUpload(target, source, env):  # pylint: disable=W0613,W0621
     env.AutodetectUploadPort()
@@ -39,11 +41,13 @@ def BeforeUpload(target, source, env):  # pylint: disable=W0613,W0621
     if not upload_options.get("disable_flushing", False):
         env.FlushSerialBuffer("$UPLOAD_PORT")
 
+    before_ports = [i['port'] for i in get_serialports(use_grep=True)]
+
     if upload_options.get("use_1200bps_touch", False):
         env.TouchSerialPort("$UPLOAD_PORT", 1200)
 
     if upload_options.get("wait_for_upload_port", False):
-        env.Replace(UPLOAD_PORT=env.WaitForNewSerialPort())
+        env.Replace(UPLOAD_PORT=env.WaitForNewSerialPort(before_ports))
 
     # use only port name for BOSSA
     if "/" in env.subst("$UPLOAD_PORT"):
diff --git a/platformio/builder/tools/pioupload.py b/platformio/builder/tools/pioupload.py
index cb973b92..aeb71000 100644
--- a/platformio/builder/tools/pioupload.py
+++ b/platformio/builder/tools/pioupload.py
@@ -47,8 +47,7 @@ def TouchSerialPort(env, port, baudrate):
     sleep(0.4)
 
 
-def WaitForNewSerialPort(env):
-    before = [i['port'] for i in get_serialports(use_grep=True)]
+def WaitForNewSerialPort(env, before):
     sleep(0.5)
     new_port = None
     elapsed = 0
diff --git a/platformio/util.py b/platformio/util.py
index 221c6d9b..13a9b9e6 100644
--- a/platformio/util.py
+++ b/platformio/util.py
@@ -325,7 +325,7 @@ def get_serialports(use_grep=False):
         result.append({"port": p, "description": d, "hwid": h})
 
     # fix for PySerial
-    if not result and not use_grep:
+    if not result and not use_grep and system() == "Darwin":
         result = _grep_serial_ports()
 
     return result