diff --git a/src/pmhclib/__init__.py b/src/pmhclib/__init__.py
index e4f5d1d..03cbcf8 100644
--- a/src/pmhclib/__init__.py
+++ b/src/pmhclib/__init__.py
@@ -1,6 +1,10 @@
+# read version from installed package
+from importlib.metadata import version
+__version__ = version("pmhclib")
+
 # Import classes to be available at the top level.
 # Allows importing with:
 #     from pmhclib import PMHC
 # rather than
 #     from pmhclib.pmhc import PMHC
-from .pmhc import PMHC
+from .pmhc import PMHC, PMHCSpecification