diff --git a/README.md b/README.md
index 3d92b9e..ff35667 100644
--- a/README.md
+++ b/README.md
@@ -28,6 +28,17 @@ Version 2.0.0 of `pytile` makes several breaking, but necessary changes:
 If you wish to continue using the previous, synchronous version of `pytile`,
 make sure to pin version 1.1.0.
 
+# Python Versions
+
+`pytile` is currently supported on:
+
+* Python 3.5
+* Python 3.6
+* Python 3.7
+
+However, running the test suite currently requires Python 3.6 or higher; tests
+run on Python 3.5 will fail.
+
 # Installation
 
 ```python
diff --git a/setup.py b/setup.py
index 29351b7..e192019 100644
--- a/setup.py
+++ b/setup.py
@@ -19,7 +19,7 @@
 URL = 'https://github.com/bachya/pytile'
 EMAIL = 'bachya1208@gmail.com'
 AUTHOR = 'Aaron Bach'
-REQUIRES_PYTHON = '>=3.6.0'
+REQUIRES_PYTHON = '>=3.5.3'
 VERSION = None
 
 # What packages are required for this module to be executed?
@@ -118,6 +118,7 @@ def run(self):
         'License :: OSI Approved :: MIT License',
         'Programming Language :: Python',
         'Programming Language :: Python :: 3',
+        'Programming Language :: Python :: 3.5',
         'Programming Language :: Python :: 3.6',
         'Programming Language :: Python :: 3.7',
         'Programming Language :: Python :: Implementation :: CPython',