diff --git a/src/allmydata/__init__.py b/src/allmydata/__init__.py
index e57b5e624..06f8e15c6 100644
--- a/src/allmydata/__init__.py
+++ b/src/allmydata/__init__.py
@@ -144,7 +144,8 @@ def normalized_version(verstr, what=None):
 
 def get_package_versions_and_locations():
     import warnings
-    from _auto_deps import package_imports, deprecation_messages, deprecation_imports
+    from _auto_deps import package_imports, deprecation_messages,  \
+        deprecation_imports, user_warning_messages
 
     def package_dir(srcfile):
         return os.path.dirname(os.path.dirname(os.path.normcase(os.path.realpath(srcfile))))
@@ -161,11 +162,14 @@ def get_package_versions_and_locations():
         message="BaseException.message has been deprecated as of Python 2.6",
         append=True)
 
-    # This is to suppress various DeprecationWarnings that occur when modules are imported.
-    # See http://allmydata.org/trac/tahoe/ticket/859 and http://divmod.org/trac/ticket/2994 .
+    # This is to suppress various DeprecationWarnings and UserWarnings that
+    # occur when modules are imported.  See #859, #1435 and
+    # http://divmod.org/trac/ticket/2994 .
 
     for msg in deprecation_messages:
         warnings.filterwarnings("ignore", category=DeprecationWarning, message=msg, append=True)
+    for msg in user_warning_messages:
+        warnings.filterwarnings("ignore", category=UserWarning, message=msg, append=True)
     try:
         for modulename in deprecation_imports:
             try:
@@ -175,6 +179,8 @@ def get_package_versions_and_locations():
     finally:
         for ign in deprecation_messages:
             warnings.filters.pop()
+        for ign in user_warning_messages:
+            warnings.filters.pop()
 
     packages = []
 
diff --git a/src/allmydata/_auto_deps.py b/src/allmydata/_auto_deps.py
index 68ef9f683..077c957b5 100644
--- a/src/allmydata/_auto_deps.py
+++ b/src/allmydata/_auto_deps.py
@@ -15,8 +15,7 @@ install_requires = [
     "simplejson >= 1.4",
 
     # zope.interface 3.6.3 and 3.6.4 are incompatible with Nevow (#1435).
-    # 3.6.5 is compatible but fails tests due to an unsuppressed warning.
-    "zope.interface <= 3.6.2, >= 3.6.6",
+    "zope.interface <= 3.6.2, >= 3.6.5",
 
     # On Windows we need at least Twisted 9.0 to avoid an indirect dependency on pywin32.
     # On Linux we need at least Twisted 10.1.0 for inotify support used by the drop-upload
@@ -124,3 +123,7 @@ deprecation_imports = [
     'twisted.python.filepath',
     'Crypto.Hash.SHA',
 ]
+
+user_warning_messages = [
+    "Hashing uninitialized InterfaceClass instance",
+]