diff --git a/changelog/481.bugfix.rst b/changelog/481.bugfix.rst
new file mode 100644
index 00000000..4890c352
--- /dev/null
+++ b/changelog/481.bugfix.rst
@@ -0,0 +1 @@
+``PluginManager.get_plugins()`` no longer returns ``None`` for blocked plugins.
diff --git a/src/pluggy/_manager.py b/src/pluggy/_manager.py
index ce1e107a..a9eb4a48 100644
--- a/src/pluggy/_manager.py
+++ b/src/pluggy/_manager.py
@@ -291,7 +291,7 @@ def parse_hookspec_opts(
 
     def get_plugins(self) -> set[Any]:
         """Return a set of all registered plugin objects."""
-        return set(self._name2plugin.values())
+        return {x for x in self._name2plugin.values() if x is not None}
 
     def is_registered(self, plugin: _Plugin) -> bool:
         """Return whether the plugin is already registered."""
diff --git a/testing/test_pluginmanager.py b/testing/test_pluginmanager.py
index d3bcac4e..9b570f84 100644
--- a/testing/test_pluginmanager.py
+++ b/testing/test_pluginmanager.py
@@ -100,15 +100,19 @@ class A:
     assert name is not None
     assert pm.is_registered(a1)
     assert not pm.is_blocked(name)
+    assert pm.get_plugins() == {a1}
+
     pm.set_blocked(name)
     assert pm.is_blocked(name)
     assert not pm.is_registered(a1)
+    assert pm.get_plugins() == set()
 
     pm.set_blocked("somename")
     assert pm.is_blocked("somename")
     assert not pm.register(A(), "somename")
     pm.unregister(name="somename")
     assert pm.is_blocked("somename")
+    assert pm.get_plugins() == set()
 
     # Unblock.
     assert not pm.unblock("someothername")