diff --git a/Lib/defcon/test/testTools.py b/Lib/defcon/test/testTools.py
index 5762fe35..f88066c1 100644
--- a/Lib/defcon/test/testTools.py
+++ b/Lib/defcon/test/testTools.py
@@ -79,7 +79,7 @@ def __init__(self, name=None):
         self.stack = []
 
     def __repr__(self):
-        return "<_TestObservable {name} {id}".format(name=self.name, id=id(self))
+        return "<_TestObservable {name} {id}>".format(name=self.name, id=id(self))
 
     def notificationCallback(self, notification):
         print(notification.name, notification.object.name)
diff --git a/Lib/defcon/test/tools/test_notifications.py b/Lib/defcon/test/tools/test_notifications.py
index 8b42fe88..01aa6ca0 100644
--- a/Lib/defcon/test/tools/test_notifications.py
+++ b/Lib/defcon/test/tools/test_notifications.py
@@ -429,7 +429,8 @@ def test_addObserver_identifier(self):
             dict(observer=observer, observable=observable, notification="A", identifier="identifier1"),
             dict(observer=observer, observable=observable, notification="B", identifier="identifier2")
         ]
-        self.assertEqual(center.findObservations(), expected)
+        result = center.findObservations()
+        self.assertEqual(result, expected)
 
     def test_addObserver_identifierDuplicate(self):
         center = NotificationCenter()
@@ -528,5 +529,18 @@ def test_findObservations_all(self):
         result = center.findObservations(observer=observer1, notification="A", observable=observable1, identifier="identifier1-1-A")
         self.assertEqual(result, expected)
 
+    def test_findObservations_noIdentifier(self):
+        center = NotificationCenter()
+        observable = _TestObservable(center, "Observable")
+        observer = NotificationTestObserver()
+        center.addObserver(observer, "notificationCallback", "A", observable, identifier="identifier1")
+        center.addObserver(observer, "notificationCallback", "B", observable)
+        expected = [
+            dict(observer=observer, observable=observable, notification="A", identifier="identifier1"),
+            dict(observer=observer, observable=observable, notification="B", identifier=None)
+        ]
+        result = center.findObservations()
+        self.assertEqual(result, expected)
+
 if __name__ == "__main__":
     unittest.main()
diff --git a/Lib/defcon/tools/notifications.py b/Lib/defcon/tools/notifications.py
index 8a7f8c27..9ee631a1 100644
--- a/Lib/defcon/tools/notifications.py
+++ b/Lib/defcon/tools/notifications.py
@@ -430,17 +430,20 @@ def findObservations(self, observer=None, notification=None, observable=None, id
         if observable is not None:
             observable = weakref.ref(observable)
         found = []
-        for (otherNotification, otherObservable), observerDict in self._identifierRegistry.items():
+        for (otherNotification, otherObservable), observerDict in self._registry.items():
             if notification is not None:
                 if otherNotification != notification:
                     continue
             if observable is not None:
                 if otherObservable != observable:
                     continue
-            for otherObserver, otherIdentifier in observerDict.items():
-                if identifier is not None:
-                    if not fnmatchcase(otherIdentifier, identifier):
-                        continue
+            for otherObserver, methodName in observerDict.items():
+                otherIdentifier = None
+                if (otherNotification, otherObservable) in self._identifierRegistry:
+                    otherIdentifier = self._identifierRegistry[otherNotification, otherObservable].get(otherObserver)
+                    if otherIdentifier is not None and identifier is not None:
+                        if not fnmatchcase(otherIdentifier, identifier):
+                            continue
                 if observer is not None:
                     if otherObserver != observer:
                         continue