diff --git a/synapse/config/tls.py b/synapse/config/tls.py
index a45bf6d52..034f9a7bf 100644
--- a/synapse/config/tls.py
+++ b/synapse/config/tls.py
@@ -13,7 +13,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-from ._base import Config, ConfigError
+from ._base import Config
 
 from OpenSSL import crypto
 import subprocess