diff --git a/nixos/modules/services/misc/matrix-synapse.nix b/nixos/modules/services/misc/matrix-synapse.nix
index 018fac386163d..0f4eb2ccfcad4 100644
--- a/nixos/modules/services/misc/matrix-synapse.nix
+++ b/nixos/modules/services/misc/matrix-synapse.nix
@@ -79,7 +79,11 @@ turn_user_lifetime: "${cfg.turn_user_lifetime}"
 user_creation_max_duration: ${cfg.user_creation_max_duration}
 bcrypt_rounds: ${cfg.bcrypt_rounds}
 allow_guest_access: ${boolToString cfg.allow_guest_access}
-trusted_third_party_id_servers: ${builtins.toJSON cfg.trusted_third_party_id_servers}
+
+account_threepid_delegates:
+  ${optionalString (cfg.account_threepid_delegates.email != null) "email: ${cfg.account_threepid_delegates.email}"}
+  ${optionalString (cfg.account_threepid_delegates.msisdn != null) "msisdn: ${cfg.account_threepid_delegates.msisdn}"}
+
 room_invite_state_types: ${builtins.toJSON cfg.room_invite_state_types}
 ${optionalString (cfg.macaroon_secret_key != null) ''
   macaroon_secret_key: "${cfg.macaroon_secret_key}"
@@ -102,6 +106,7 @@ perspectives:
     '') cfg.servers)}
     }
   }
+redaction_retention_period: ${toString cfg.redaction_retention_period}
 app_service_config_files: ${builtins.toJSON cfg.app_service_config_files}
 
 ${cfg.extraConfig}
@@ -552,14 +557,18 @@ in {
           accessible to anonymous users.
         '';
       };
-      trusted_third_party_id_servers = mkOption {
-        type = types.listOf types.str;
-        default = [
-          "matrix.org"
-          "vector.im"
-        ];
+      account_threepid_delegates.email = mkOption {
+        type = types.nullOr types.str;
+        default = null;
         description = ''
-          The list of identity servers trusted to verify third party identifiers by this server.
+          Delegate email sending to https://example.org
+        '';
+      };
+      account_threepid_delegates.msisdn = mkOption {
+        type = types.nullOr types.str;
+        default = null;
+        description = ''
+          Delegate SMS sending to this local process (https://localhost:8090)
         '';
       };
       room_invite_state_types = mkOption {
@@ -600,6 +609,13 @@ in {
           A list of application service config file to use
         '';
       };
+      redaction_retention_period = mkOption {
+        type = types.int;
+        default = 7;
+        description = ''
+          How long to keep redacted events in unredacted form in the database.
+        '';
+      };
       extraConfig = mkOption {
         type = types.lines;
         default = "";
@@ -699,4 +715,12 @@ in {
       };
     };
   };
+
+  imports = [
+    (mkRemovedOptionModule [ "services" "matrix-synapse" "trusted_third_party_id_servers" ] ''
+      The `trusted_third_party_id_servers` option as been removed in `matrix-synapse` v1.4.0
+      as the behavior is now obsolete.
+    '')
+  ];
+
 }
diff --git a/pkgs/servers/matrix-synapse/default.nix b/pkgs/servers/matrix-synapse/default.nix
index ab9a69afdcb8d..58a5c66d3b073 100644
--- a/pkgs/servers/matrix-synapse/default.nix
+++ b/pkgs/servers/matrix-synapse/default.nix
@@ -23,11 +23,11 @@ let
 
 in buildPythonApplication rec {
   pname = "matrix-synapse";
-  version = "1.3.1";
+  version = "1.4.0";
 
   src = fetchPypi {
     inherit pname version;
-    sha256 = "1nz9bhy5hraa1h7100vr0innz8npnpha6xr9j2ln7h3cgwv73739";
+    sha256 = "1y8yhzsf2lk2d7v4l61rpy4918c0qz276j79q88l9yazb6gw5pkk";
   };
 
   patches = [
@@ -83,6 +83,6 @@ in buildPythonApplication rec {
     homepage = https://matrix.org;
     description = "Matrix reference homeserver";
     license = licenses.asl20;
-    maintainers = with maintainers; [ ralith roblabla ekleog pacien ];
+    maintainers = with maintainers; [ ralith roblabla ekleog pacien ma27 ];
   };
 }