diff --git a/doc/source/changes.rst b/doc/source/changes.rst
index aa5b3f1..0c2907a 100644
--- a/doc/source/changes.rst
+++ b/doc/source/changes.rst
@@ -2,6 +2,16 @@ Changelog
 =========
 
 
+1.999.1 - 2017-04-06
+---------------------
+.. note::
+
+    This version is only meant to be used internally at SmarterTravel as a transition
+    step between two load balancers. As such, it is not available on PyPI.
+
+* Add support for new Python SSL constant ``PROTOCOL_TLS`` to allow negotiation of SSL
+  versions between the client and server.
+
 1.999.0 - 2017-04-05
 --------------------
 .. note::
diff --git a/warthog/__init__.py b/warthog/__init__.py
index 9af2178..6d1434b 100644
--- a/warthog/__init__.py
+++ b/warthog/__init__.py
@@ -14,4 +14,4 @@ warthog
 Simple client for A10 load balancers.
 """
 
-__version__ = '1.999.0'
+__version__ = '1.999.1'
diff --git a/warthog/ssl.py b/warthog/ssl.py
index dea969f..92b4b3d 100644
--- a/warthog/ssl.py
+++ b/warthog/ssl.py
@@ -22,7 +22,7 @@ SSL related constants used by Warthog
 
 PROTOCOL_SSLv3 = 1
 
-PROTOCOL_SSLv23 = 2
+PROTOCOL_TLS = PROTOCOL_SSLv23 = 2
 
 PROTOCOL_TLSv1 = 3
 

Unsupported TLS versions
Turns out that even if you manage to use a different SSL version, still needs to supported by the Python `ssl` module. Who knew? To this end we're going to add the new `PROTOCOL_TLS` constant (effectively the same as `PROTOCOL_SSLv23`) and use that to allow negotiation between the LB and our ancient Python version.
diff --git a/test/test_ssl.py b/test/test_ssl.py
index 9165683..1b3ebf3 100644
--- a/test/test_ssl.py
+++ b/test/test_ssl.py
@@ -21,6 +21,24 @@ def test_tls1_matches():
     assert ssl.PROTOCOL_TLSv1 == warthog.ssl.PROTOCOL_TLSv1
 
 
+def test_tls_matches_ssl23():
+    # New constant in Python 2.7.13 for negotiation of the highest
+    # supported protocol. Same value as the previous "negotiate"
+    # constant (SSLv23).
+    assert ssl.PROTOCOL_SSLv23 == warthog.ssl.PROTOCOL_TLS
+
+
+def test_tls_matches():
+    try:
+        # It's possible that we're running under an old version of Python
+        # and this constant doesn't exist (hence why warthog.ssl exists).
+        module_const = ssl.PROTOCOL_TLS
+    except AttributeError:
+        return
+
+    assert module_const == warthog.ssl.PROTOCOL_TLS
+
+    
 def test_tls1_1_matches():
     try:
         # It's possible that we're running under an old version of Python

pip install -e .
parse_log_pytest
requirements.txt
pytest
apt-get update apt-get install -y gcc
3.4
requirements.txt
pytest --no-header -rA --tb=line --color=no -p no:cacheprovider -W ignore::DeprecationWarning
attrs==22.2.0
certifi==2021.5.30
click==6.7
importlib-metadata==4.8.3
iniconfig==1.1.1
packaging==21.3
pluggy==1.0.0
py==1.11.0
pyparsing==3.1.4
pytest==7.0.1
requests==2.11.1
tomli==1.2.3
typing_extensions==4.1.1
-e git+https://github.com/smarter-travel-media/warthog.git@ccc611dd6f05482fdb81348bb972eea06d456dc7#egg=warthog
zipp==3.6.0

name: warthog
channels:
  - defaults
  - https://repo.anaconda.com/pkgs/main
  - https://repo.anaconda.com/pkgs/r
  - conda-forge
dependencies:
  - _libgcc_mutex=0.1=main
  - _openmp_mutex=5.1=1_gnu
  - ca-certificates=2025.2.25=h06a4308_0
  - certifi=2021.5.30=py36h06a4308_0
  - ld_impl_linux-64=2.40=h12ee557_0
  - libffi=3.3=he6710b0_2
  - libgcc-ng=11.2.0=h1234567_1
  - libgomp=11.2.0=h1234567_1
  - libstdcxx-ng=11.2.0=h1234567_1
  - ncurses=6.4=h6a678d5_0
  - openssl=1.1.1w=h7f8727e_0
  - pip=21.2.2=py36h06a4308_0
  - python=3.6.13=h12debd9_1
  - readline=8.2=h5eee18b_0
  - setuptools=58.0.4=py36h06a4308_0
  - sqlite=3.45.3=h5eee18b_0
  - tk=8.6.14=h39e8969_0
  - wheel=0.37.1=pyhd3eb1b0_0
  - xz=5.6.4=h5eee18b_1
  - zlib=1.2.13=h5eee18b_1
  - pip:
      - attrs==22.2.0
      - click==6.7
      - importlib-metadata==4.8.3
      - iniconfig==1.1.1
      - packaging==21.3
      - pluggy==1.0.0
      - py==1.11.0
      - pyparsing==3.1.4
      - pytest==7.0.1
      - requests==2.11.1
      - tomli==1.2.3
      - typing-extensions==4.1.1
      - zipp==3.6.0
prefix: /opt/conda/envs/warthog

test/test_ssl.py::test_tls_matches_ssl23 test/test_ssl.py::test_tls_matches
test/test_ssl.py::test_ssl3_matches
test/test_ssl.py::test_ssl23_matches test/test_ssl.py::test_tls1_matches test/test_ssl.py::test_tls1_1_matches test/test_ssl.py::test_tls1_2_matches
warthog/ssl.py warthog/__init__.py doc/source/changes.rst
warthog/ssl.py warthog/__init__.py doc/source/changes.rst