diff --git a/pygeodiff/geodifflib.py b/pygeodiff/geodifflib.py
index 68fd7137..fc4d28a7 100644
--- a/pygeodiff/geodifflib.py
+++ b/pygeodiff/geodifflib.py
@@ -44,6 +44,7 @@ def __init__(self, name):
         If name is None, the environment variable GEODIFFLIB is used. If
         that is not set, it tries to import c-extension from wheel.
         """
+        self.lib = None
         if name is None:
             name = os.getenv("GEODIFFLIB")
         if not name:
@@ -79,6 +80,10 @@ def shutdown(self):
                 from _ctypes import FreeLibrary
 
                 FreeLibrary(self.lib._handle)
+            else:
+                from _ctypes import dlclose
+
+                dlclose(self.lib._handle)
             self.lib = None
 
     def _register_functions(self):