diff --git a/src/allmydata/_auto_deps.py b/src/allmydata/_auto_deps.py
index 8a37bd34b..a4b165572 100644
--- a/src/allmydata/_auto_deps.py
+++ b/src/allmydata/_auto_deps.py
@@ -42,7 +42,8 @@ install_requires = [
     # * foolscap >= 0.12.3 provides tcp/tor/i2p connection handlers we need,
     #   and allocate_tcp_port
     # * foolscap >= 0.12.5 has ConnectionInfo and ReconnectionInfo
-    "foolscap >= 0.12.5",
+    # * foolscap >= 0.12.6 has an i2p.sam_endpoint() that takes kwargs
+    "foolscap >= 0.12.6",
 
     # Needed for SFTP.
     # pycrypto 2.2 doesn't work due to <https://bugs.launchpad.net/pycrypto/+bug/620253>
diff --git a/src/allmydata/test/test_connections.py b/src/allmydata/test/test_connections.py
index c336a5c3c..fff0e55ea 100644
--- a/src/allmydata/test/test_connections.py
+++ b/src/allmydata/test/test_connections.py
@@ -158,7 +158,7 @@ class I2P(unittest.TestCase):
         with mock.patch("foolscap.connections.i2p.default",
                         return_value=h1) as f:
             h = n._make_i2p_handler()
-            self.assertEqual(f.mock_calls, [mock.call(reactor)])
+            self.assertEqual(f.mock_calls, [mock.call(reactor, keyfile=None)])
             self.assertIdentical(h, h1)
 
     def test_samport(self):
diff --git a/src/allmydata/test/test_i2p_provider.py b/src/allmydata/test/test_i2p_provider.py
index 50fb7995f..242c7c444 100644
--- a/src/allmydata/test/test_i2p_provider.py
+++ b/src/allmydata/test/test_i2p_provider.py
@@ -221,7 +221,7 @@ class Provider(unittest.TestCase):
                 h = p.get_i2p_handler()
         cfs.assert_called_with(reactor, "ep_desc")
         self.assertIs(h, handler)
-        i2p.sam_endpoint.assert_called_with(ep)
+        i2p.sam_endpoint.assert_called_with(ep, keyfile=None)
 
     def test_handler_launch(self):
         i2p = mock.Mock()
@@ -292,7 +292,7 @@ class Provider(unittest.TestCase):
             p = i2p_provider.Provider("basedir", FakeConfig(), reactor)
         h = p.get_i2p_handler()
         self.assertIs(h, handler)
-        i2p.default.assert_called_with(reactor)
+        i2p.default.assert_called_with(reactor, keyfile=None)
 
 class Provider_CheckI2PConfig(unittest.TestCase):
     def test_default(self):
diff --git a/src/allmydata/util/i2p_provider.py b/src/allmydata/util/i2p_provider.py
index 91391e24c..10777e16a 100644
--- a/src/allmydata/util/i2p_provider.py
+++ b/src/allmydata/util/i2p_provider.py
@@ -147,13 +147,14 @@ class Provider(service.MultiService):
         sam_port = self._get_i2p_config("sam.port", None)
         launch = self._get_i2p_config("launch", False, boolean=True)
         configdir = self._get_i2p_config("i2p.configdir", None)
+        keyfile = self._get_i2p_config("dest.private_key_file", None)
 
         if sam_port:
             if launch:
                 raise ValueError("tahoe.cfg [i2p] must not set both "
                                  "sam.port and launch")
             ep = clientFromString(self._reactor, sam_port)
-            return self._i2p.sam_endpoint(ep)
+            return self._i2p.sam_endpoint(ep, keyfile=keyfile)
 
         if launch:
             executable = self._get_i2p_config("i2p.executable", None)
@@ -162,7 +163,7 @@ class Provider(service.MultiService):
         if configdir:
             return self._i2p.local_i2p(configdir)
 
-        return self._i2p.default(self._reactor)
+        return self._i2p.default(self._reactor, keyfile=keyfile)
 
     def check_dest_config(self):
         if self._get_i2p_config("dest", False, boolean=True):