diff --git a/doc/make.py b/doc/make.py

index db729853e..9e77ff613 100755

--- a/doc/make.py

+++ b/doc/make.py

@@ -339,8 +339,7 @@ def main():

     # external libraries (namely Sphinx) to compile this module and resolve

     # the import of `python_path` correctly. The latter is used to resolve

     # the import within the module, injecting it into the global namespace

-    os.environ["PYTHONPATH"] = args.python_path

-    sys.path.insert(0, args.python_path)

+    sys.path.insert(0, os.environ["PYTHONPATH"])

     globals()["pandas"] = importlib.import_module("pandas")

     # Set the matplotlib backend to the non-interactive Agg backend for all