1diff --git a/platformio/proc.py b/platformio/proc.py
2index 80e50201..15cee5a5 100644
3--- a/platformio/proc.py
4+++ b/platformio/proc.py
5@@ -181,7 +181,7 @@ def copy_pythonpath_to_osenv():
6 conditions.append(isdir(join(p, "click")) or isdir(join(p, "platformio")))
7 if all(conditions):
8 _PYTHONPATH.append(p)
9- os.environ["PYTHONPATH"] = os.pathsep.join(_PYTHONPATH)
10+ os.environ["PYTHONPATH"] = os.pathsep.join(sys.path)
11
12
13 def where_is_program(program, envpath=None):