Index: twisted/test/test_strcred.py
===================================================================
--- twisted/test/test_strcred.py	(revision 34525)
+++ twisted/test/test_strcred.py	(working copy)
@@ -352,6 +352,10 @@
     except ImportError:
         skip = "PyCrypto is not available"
 
+    try:
+        from twisted import conch
+    except ImportError:
+        skip = "Twisted Conch is not available"
 
     def test_isChecker(self):
         """