diff --git a/polymorphic/__init__.py b/polymorphic/__init__.py
index 128269f9..afd1dfc1 100644
--- a/polymorphic/__init__.py
+++ b/polymorphic/__init__.py
@@ -6,9 +6,7 @@
 Please see LICENSE and AUTHORS for more information.
 """
 
-import pkg_resources
+VERSION = "3.1.0"
 
-try:
-    __version__ = pkg_resources.require("django-polymorphic")[0].version
-except pkg_resources.DistributionNotFound:
-    __version__ = None  # for RTD among others
+# version synonym for backwards compatibility
+__version__ = VERSION
diff --git a/setup.cfg b/setup.cfg
index 09ff55a5..d3ca3dde 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -1,6 +1,6 @@
 [metadata]
 name = django-polymorphic
-version = 3.1.0
+version = attr: polymorphic.VERSION
 description = Seamless polymorphic inheritance for Django models
 long_description = file:README.rst
 author = Bert Constantin