diff --git a/docs/projectconf.rst b/docs/projectconf.rst
index 13b49702..880ad68a 100644
--- a/docs/projectconf.rst
+++ b/docs/projectconf.rst
@@ -621,8 +621,9 @@ Example, specify own upload command for :ref:`platform_atmelavr`:
 .. code-block:: python
 
     Import('env')
+    from base64 import b64decode
 
-    env.Replace(UPLOADHEXCMD='"$UPLOADER" ${ARGUMENTS.get("custom_option")} --uploader --flags')
+    env.Replace(UPLOADHEXCMD='"$UPLOADER" ' + b64decode(ARGUMENTS.get("CUSTOM_OPTION")) + ' --uploader --flags')
 
     # uncomment line below to see environment variables
     # print env.Dump()
diff --git a/platformio/commands/run.py b/platformio/commands/run.py
index b19e30ab..652b204a 100644
--- a/platformio/commands/run.py
+++ b/platformio/commands/run.py
@@ -203,7 +203,7 @@ class EnvironmentProcessor(object):
             # warn about unknown options
             if k not in self.KNOWN_OPTIONS:
                 click.secho(
-                    "Warning! Ignore unknown `%s` option from `[env:]` section"
+                    "Detected non-PlatformIO `%s` option in `[env:]` section"
                     % k,
                     fg="yellow")
             result[k] = v