diff --git a/tests/test_interval.py b/tests/test_interval.py
index 36504ed..978b248 100644
--- a/tests/test_interval.py
+++ b/tests/test_interval.py
@@ -341,7 +341,7 @@ class TestIntervalTree:
         render(iset, "In-order insertion")
 
 class TestIntervalSpeed:
-    #@unittest.skip("this is slow")
+    @unittest.skip("this is slow")
     def test_interval_speed(self):
         import yappi
         import time
diff --git a/tests/test_mustclose.py b/tests/test_mustclose.py
index c81514c..08161a3 100644
--- a/tests/test_mustclose.py
+++ b/tests/test_mustclose.py
@@ -9,6 +9,7 @@ from testutil.helpers import *
 
 import sys
 import cStringIO
+import gc
 
 err = cStringIO.StringIO()
 
@@ -23,8 +24,22 @@ class Foo:
     def close(self):
         fprintf(err, "Closing\n")
 
-@nilmdb.utils.must_close(errorfile = err)
+@nilmdb.utils.must_close(errorfile = err, wrap_verify = True)
 class Bar:
+    def __init__(self):
+        fprintf(err, "Init\n")
+
+    def __del__(self):
+        fprintf(err, "Deleting\n")
+
+    def close(self):
+        fprintf(err, "Closing\n")
+
+    def blah(self):
+        fprintf(err, "Blah\n")
+
+@nilmdb.utils.must_close(errorfile = err)
+class Baz:
     pass
 
 class TestMustClose(object):
@@ -34,26 +49,51 @@ class TestMustClose(object):
         # garbage collect the object (and call its __del__ function)
         # right after a "del x".
 
+        # Trigger error
+        err.truncate()
         x = Foo()
         del x
+        gc.collect()
         eq_(err.getvalue(),
             "Init\n"
             "error: Foo.close() wasn't called!\n"
             "Deleting\n")
 
+        # No error
         err.truncate(0)
-
         y = Foo()
         y.close()
         del y
+        gc.collect()
         eq_(err.getvalue(),
             "Init\n"
             "Closing\n"
             "Deleting\n")
 
+        # Verify errors
         err.truncate(0)
-
         z = Bar()
+        z.blah()
         z.close()
+        with assert_raises(AssertionError):
+            z.blah()
+        # Since the most recent assertion references 'z',
+        # we need to raise another assertion here so that
+        # 'z' will get properly deleted.
+        with assert_raises(AssertionError):
+            raise AssertionError()
         del z
+        gc.collect()
+        eq_(err.getvalue(),
+            "Init\n"
+            "Blah\n"
+            "Closing\n"
+            "Deleting\n")
+
+        # Class with missing methods
+        err.truncate(0)
+        w = Baz()
+        w.close()
+        del w
         eq_(err.getvalue(), "")
+