diff --git a/pkgs/servers/matrix-synapse/default.nix b/pkgs/servers/matrix-synapse/default.nix
index 66d9e7258f4c..714ff9d002c8 100644
--- a/pkgs/servers/matrix-synapse/default.nix
+++ b/pkgs/servers/matrix-synapse/default.nix
@@ -26,7 +26,7 @@ buildPythonPackage rec {
   propagatedBuildInputs = with pythonPackages; [
     blist canonicaljson daemonize dateutil frozendict pillow pybcrypt pyasn1
     pydenticon pymacaroons-pynacl pynacl pyopenssl pysaml2 pytz requests2
-    service-identity signedjson systemd twisted15 ujson unpaddedbase64 pyyaml
+    service-identity signedjson systemd twisted ujson unpaddedbase64 pyyaml
     matrix-angular-sdk
   ];
 
diff --git a/pkgs/top-level/python-packages.nix b/pkgs/top-level/python-packages.nix
index a863a29780ec..dd3df2310c9c 100644
--- a/pkgs/top-level/python-packages.nix
+++ b/pkgs/top-level/python-packages.nix
@@ -18216,7 +18216,7 @@ in modules // {
       md5 = "f16f4237c9ee483a0cd13208849d96ad";
     };
 
-    propagatedBuildInputs = with self; [ twisted15 ];
+    propagatedBuildInputs = with self; [ twisted ];
 
     meta = {
       description = "setuptools plug-in that helps run unit tests built with the \"Trial\" framework (from Twisted)";
@@ -20176,7 +20176,7 @@ in modules // {
     };
   };
 
-  twisted = buildPythonPackage rec {
+  twisted_11 = buildPythonPackage rec {
     # NOTE: When updating please check if new versions still cause issues
     # to packages like carbon (http://stackoverflow.com/questions/19894708/cant-start-carbon-12-04-python-error-importerror-cannot-import-name-daem)
     disabled = isPy3k;
@@ -20207,7 +20207,7 @@ in modules // {
     };
   };
 
-  twisted15 = buildPythonPackage rec {
+  twisted = buildPythonPackage rec {
     disabled = isPy3k;
 
     name = "Twisted-15.5.0";