diff --git a/Dockerfile b/Dockerfile
index 5dd55fcbd4a41d692f21dedb54eea38eb7656671..7d8f557577cfe40367add95b1fa7cf53eed172c5 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -39,7 +39,7 @@ RUN pyenv install 3.5.10 && \
     pyenv install pypy3.6-7.3.1 && \
     pyenv global 3.9.0
 RUN /.pyenv/versions/3.9.0/bin/python3.9 -m pip install --upgrade pip
-RUN pip install tox
+RUN pip install tox twine
 
 RUN mkdir -p /usr/src/ibapi && \
     chmod a+rwx -R /usr/src/ibapi && \
diff --git a/src/ibapi/__init__.py b/src/ibapi/__init__.py
index f10edead9cfa953ad8ac6565e6f7bd5b1e9923ad..9cc68d4ebbf6f0c20ad40603b1cbc0a187f2b3a2 100644
--- a/src/ibapi/__init__.py
+++ b/src/ibapi/__init__.py
@@ -8,11 +8,14 @@ Copyright (C) 2019 Interactive Brokers LLC. All rights reserved. This code is su
 VERSION = {
     'major': 9,
     'minor': 81,
-    'micro': 1}
+    'patch': 1,
+    'extra': 1}
 
 
 def get_version_string():
-    version = '{major}.{minor}.{micro}'.format(**VERSION)
+    version = '{major}.{minor}.{patch}-{extra}'.format(**VERSION)
+    if( VERSION['extra'] <= 0):
+        version = '{major}.{minor}.{patch}'.format(**VERSION)
     return version
 
 __version__ = get_version_string()