diff --git a/CHANGES.md b/CHANGES.md
index ee1eb9a58..518781f93 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -1,3 +1,27 @@
+Synapse 1.56.0 (2022-04-05)
+===========================
+
+Synapse will now refuse to start up if open registration is enabled, in order to help mitigate
+abuse across the federation. If you would like
+to provide registration to anyone, consider adding [email](https://github.com/matrix-org/synapse/blob/8a519f8abc6de772167c2cca101d22ee2052fafc/docs/sample_config.yaml#L1285),
+[recaptcha](https://matrix-org.github.io/synapse/v1.56/CAPTCHA_SETUP.html)
+or [token-based](https://matrix-org.github.io/synapse/v1.56/usage/administration/admin_api/registration_tokens.html) verification
+in order to prevent automated registration from bad actors.
+This check can be disabled by setting the `enable_registration_without_verification` option in your
+homeserver configuration file to `true`. More details are available in the
+[upgrade notes](https://matrix-org.github.io/synapse/v1.56/upgrade.html#open-registration-without-verification-is-now-disabled-by-default).
+
+Synapse will additionally now refuse to start when using PostgreSQL with a non-`C` values for `COLLATE` and `CTYPE`, unless
+the config flag `allow_unsafe_locale`, found in the database section of the configuration file, is set to `true`. See the
+[upgrade notes](https://matrix-org.github.io/synapse/v1.56/upgrade#change-in-behaviour-for-postgresql-databases-with-unsafe-locale)
+for details.
+
+Internal Changes
+----------------
+
+- Bump the version of `black` for compatibility with the latest `click` release. ([\#12320](https://github.com/matrix-org/synapse/issues/12320))
+
+
 Synapse 1.56.0rc1 (2022-03-29)
 ==============================
 
@@ -33,7 +57,7 @@ Internal Changes
 - Rename `shared_rooms` to `mutual_rooms` ([MSC2666](https://github.com/matrix-org/matrix-doc/pull/2666)), as per proposal changes. ([\#12036](https://github.com/matrix-org/synapse/issues/12036))
 - Remove check on `update_user_directory` for shared rooms handler ([MSC2666](https://github.com/matrix-org/matrix-doc/pull/2666)), and update/expand documentation. ([\#12038](https://github.com/matrix-org/synapse/issues/12038))
 - Refactor `create_new_client_event` to use a new parameter, `state_event_ids`, which accurately describes the usage with [MSC2716](https://github.com/matrix-org/matrix-doc/pull/2716) instead of abusing `auth_event_ids`. ([\#12083](https://github.com/matrix-org/synapse/issues/12083), [\#12304](https://github.com/matrix-org/synapse/issues/12304))
-- Refuse to start if registration is enabled without email, captcha, or token-based verification unless the new config flag `enable_registration_without_verification` is set. ([\#12091](https://github.com/matrix-org/synapse/issues/12091))
+- Refuse to start if registration is enabled without email, captcha, or token-based verification unless the new config flag `enable_registration_without_verification` is set to `true`. ([\#12091](https://github.com/matrix-org/synapse/issues/12091), [\#12322](https://github.com/matrix-org/synapse/issues/12322))
 - Add tests for database transaction callbacks. ([\#12198](https://github.com/matrix-org/synapse/issues/12198))
 - Handle cancellation in `DatabasePool.runInteraction`. ([\#12199](https://github.com/matrix-org/synapse/issues/12199))
 - Add missing type hints for cache storage. ([\#12216](https://github.com/matrix-org/synapse/issues/12216))
@@ -6441,4 +6465,4 @@ Internal Changes
 - Don't run CI build checks until sample config check has passed. ([\#5370](https://github.com/matrix-org/synapse/issues/5370))
 - Automatically retry buildkite builds (max twice) when an agent is lost. ([\#5380](https://github.com/matrix-org/synapse/issues/5380))
 
-**Changelogs for versions older than 1.0.0 can be found [here](CHANGES-pre-1.0.md).**
\ No newline at end of file
+**Changelogs for versions older than 1.0.0 can be found [here](CHANGES-pre-1.0.md).**
diff --git a/debian/changelog b/debian/changelog
index d04954457..903d98af0 100644
--- a/debian/changelog
+++ b/debian/changelog
@@ -1,3 +1,9 @@
+matrix-synapse-py3 (1.56.0) stable; urgency=medium
+
+  * New synapse release 1.56.0.
+
+ -- Synapse Packaging team <packages@matrix.org>  Tue, 05 Apr 2022 12:38:39 +0100
+
 matrix-synapse-py3 (1.56.0~rc1) stable; urgency=medium
 
   * New synapse release 1.56.0~rc1.
diff --git a/docs/upgrade.md b/docs/upgrade.md
index f6d226526..de3444930 100644
--- a/docs/upgrade.md
+++ b/docs/upgrade.md
@@ -100,6 +100,11 @@ deployments where no applciation services are in use can be upgraded as normal.
 
 # Upgrading to v1.56.0
 
+## Open registration without verification is now disabled by default
+
+Synapse will refuse to start if registration is enabled without email, captcha, or token-based verification unless the new config
+flag `enable_registration_without_verification` is set to "true".
+
 ## Groups/communities feature has been deprecated
 
 The non-standard groups/communities feature in Synapse has been deprecated and will
@@ -121,12 +126,6 @@ for more information and instructions on how to fix a database with incorrect va
 
 # Upgrading to v1.55.0
 
-## Open registration without verification is now disabled by default
-
-Synapse will refuse to start if registration is enabled without email, captcha, or token-based verification unless the new config 
-flag `enable_registration_without_verification` is set to "true".
-
-
 ## `synctl` script has been moved
 
 The `synctl` script
diff --git a/synapse/__init__.py b/synapse/__init__.py
index 0960305d7..2e6510537 100644
--- a/synapse/__init__.py
+++ b/synapse/__init__.py
@@ -68,7 +68,7 @@ try:
 except ImportError:
     pass
 
-__version__ = "1.56.0rc1"
+__version__ = "1.56.0"
 
 if bool(os.environ.get("SYNAPSE_TEST_PATCH_LOG_CONTEXTS", False)):
     # We import here so that we don't have to install a bunch of deps when
diff --git a/synapse/python_dependencies.py b/synapse/python_dependencies.py
index 8419ab3ac..d02cca0bb 100644
--- a/synapse/python_dependencies.py
+++ b/synapse/python_dependencies.py
@@ -48,7 +48,7 @@ REQUIREMENTS = [
     "unpaddedbase64>=1.1.0",
     "canonicaljson>=1.4.0",
     # we use the type definitions added in signedjson 1.1.
-    "signedjson>=1.1.0",
+    "signedjson>=1.1.0,<=1.1.1",
     "pynacl>=1.2.1",
     "idna>=2.5",
     # validating SSL certs for IP addresses requires service_identity 18.1.