diff --git a/micropipenv.py b/micropipenv.py
index 7a592d5..4f13ff3 100755
--- a/micropipenv.py
+++ b/micropipenv.py
@@ -47,7 +47,7 @@
 from urllib.parse import urlparse
 
 _LOGGER = logging.getLogger(__title__)
-_SUPPORTED_PIP_STR = ">=9,<=20.3"  # Respects requirement in setup.py and latest pip to release date.
+_SUPPORTED_PIP_STR = ">=9,<=20.3.1"  # Respects requirement in setup.py and latest pip to release date.
 
 try:
     from pip import __version__ as pip_version