diff --git a/CHANGES.md b/CHANGES.md
index 860e89ed99..f3ba4a454f 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -1,3 +1,52 @@
+# Synapse 1.88.0rc1 (2023-07-11)
+
+Note that the minimum supported version of Python is now 3.8, as Python 3.7 is now [end-of-life](https://devguide.python.org/versions/).
+
+### Features
+
+- Add `not_user_type` param to the [list accounts admin API](https://matrix-org.github.io/synapse/v1.88/admin_api/user_admin_api.html#list-accounts). ([\#15844](https://github.com/matrix-org/synapse/issues/15844))
+
+### Bugfixes
+
+- Pin `pydantic` to `^=1.7.4` to avoid backwards-incompatible API changes from the 2.0.0 release.
+  Contributed by @PaarthShah. ([\#15862](https://github.com/matrix-org/synapse/issues/15862))
+- Correctly resize thumbnails with pillow version >=10. ([\#15876](https://github.com/matrix-org/synapse/issues/15876))
+
+### Improved Documentation
+
+- Fixed header levels on the [Admin API "Users"](https://matrix-org.github.io/synapse/v1.87/admin_api/user_admin_api.html) documentation page. Contributed by @sumnerevans at @beeper. ([\#15852](https://github.com/matrix-org/synapse/issues/15852))
+- Remove deprecated `worker_replication_host`, `worker_replication_http_port` and `worker_replication_http_tls` configuration options. ([\#15872](https://github.com/matrix-org/synapse/issues/15872))
+
+### Deprecations and Removals
+
+- Remove support for Python 3.7 and hence for Debian Buster. ([\#15851](https://github.com/matrix-org/synapse/issues/15851), [\#15892](https://github.com/matrix-org/synapse/issues/15892), [\#15893](https://github.com/matrix-org/synapse/issues/15893))
+- Remove deprecated `worker_replication_host`, `worker_replication_http_port` and `worker_replication_http_tls` configuration options. ([\#15860](https://github.com/matrix-org/synapse/issues/15860))
+
+### Internal Changes
+
+- Add foreign key constraint to `event_forward_extremities`. ([\#15751](https://github.com/matrix-org/synapse/issues/15751), [\#15907](https://github.com/matrix-org/synapse/issues/15907))
+- Add read/write style cross-worker locks. ([\#15782](https://github.com/matrix-org/synapse/issues/15782))
+- Stop writing to column `user_id` of tables `profiles` and `user_filters`. ([\#15787](https://github.com/matrix-org/synapse/issues/15787))
+- Use lower isolation level when cleaning old presence stream data to avoid serialization errors. ([\#15826](https://github.com/matrix-org/synapse/issues/15826))
+- Add tracing to media `/upload` code paths. ([\#15850](https://github.com/matrix-org/synapse/issues/15850), [\#15888](https://github.com/matrix-org/synapse/issues/15888))
+- Add a timeout that aborts any Postgres statement taking more than 1 hour. ([\#15853](https://github.com/matrix-org/synapse/issues/15853))
+- Fix the `devenv up` configuration which was ignoring the config overrides. ([\#15854](https://github.com/matrix-org/synapse/issues/15854))
+- Optimised cleanup of old entries in `device_lists_stream`. ([\#15861](https://github.com/matrix-org/synapse/issues/15861))
+- Update the Matrix clients link in the _It works! Synapse is running_ landing page. ([\#15874](https://github.com/matrix-org/synapse/issues/15874))
+- Fix building Synapse with the nightly Rust compiler. ([\#15906](https://github.com/matrix-org/synapse/issues/15906))
+- Add `Server` to Access-Control-Expose-Headers header. ([\#15908](https://github.com/matrix-org/synapse/issues/15908))
+
+### Updates to locked dependencies
+
+* Bump authlib from 1.2.0 to 1.2.1. ([\#15864](https://github.com/matrix-org/synapse/issues/15864))
+* Bump importlib-metadata from 6.6.0 to 6.7.0. ([\#15865](https://github.com/matrix-org/synapse/issues/15865))
+* Bump lxml from 4.9.2 to 4.9.3. ([\#15897](https://github.com/matrix-org/synapse/issues/15897))
+* Bump regex from 1.8.4 to 1.9.1. ([\#15902](https://github.com/matrix-org/synapse/issues/15902))
+* Bump ruff from 0.0.275 to 0.0.277. ([\#15900](https://github.com/matrix-org/synapse/issues/15900))
+* Bump sentry-sdk from 1.25.1 to 1.26.0. ([\#15867](https://github.com/matrix-org/synapse/issues/15867))
+* Bump serde_json from 1.0.99 to 1.0.100. ([\#15901](https://github.com/matrix-org/synapse/issues/15901))
+* Bump types-pyopenssl from 23.2.0.0 to 23.2.0.1. ([\#15866](https://github.com/matrix-org/synapse/issues/15866))
+
 # Synapse 1.87.0 (2023-07-04)
 
 Please note that this will be the last release of Synapse that is compatible with
diff --git a/changelog.d/15751.misc b/changelog.d/15751.misc
deleted file mode 100644
index e0ecea6c2f..0000000000
--- a/changelog.d/15751.misc
+++ /dev/null
@@ -1 +0,0 @@
-Add foreign key constraint to `event_forward_extremities`.
diff --git a/changelog.d/15782.misc b/changelog.d/15782.misc
deleted file mode 100644
index aae493b973..0000000000
--- a/changelog.d/15782.misc
+++ /dev/null
@@ -1 +0,0 @@
-Add read/write style cross-worker locks.
diff --git a/changelog.d/15787.misc b/changelog.d/15787.misc
deleted file mode 100644
index bd7536d36e..0000000000
--- a/changelog.d/15787.misc
+++ /dev/null
@@ -1 +0,0 @@
-Stop writing to column `user_id` of tables `profiles` and `user_filters`.
diff --git a/changelog.d/15826.misc b/changelog.d/15826.misc
deleted file mode 100644
index 88903f3f7c..0000000000
--- a/changelog.d/15826.misc
+++ /dev/null
@@ -1 +0,0 @@
-Use lower isolation level when cleaning old presence stream data to avoid serialization errors.
diff --git a/changelog.d/15844.feature b/changelog.d/15844.feature
deleted file mode 100644
index c220055d41..0000000000
--- a/changelog.d/15844.feature
+++ /dev/null
@@ -1 +0,0 @@
-Add `not_user_type` param to the list accounts admin API.
diff --git a/changelog.d/15850.misc b/changelog.d/15850.misc
deleted file mode 100644
index 0e49ab23fe..0000000000
--- a/changelog.d/15850.misc
+++ /dev/null
@@ -1 +0,0 @@
-Add tracing to media `/upload` code paths.
diff --git a/changelog.d/15851.removal b/changelog.d/15851.removal
deleted file mode 100644
index e08df4c136..0000000000
--- a/changelog.d/15851.removal
+++ /dev/null
@@ -1 +0,0 @@
-Remove support for Python 3.7.
diff --git a/changelog.d/15852.doc b/changelog.d/15852.doc
deleted file mode 100644
index 060b55d106..0000000000
--- a/changelog.d/15852.doc
+++ /dev/null
@@ -1 +0,0 @@
-Fixed header levels on the Admin API "Users" documentation page. Contributed by @sumnerevans at @beeper.
diff --git a/changelog.d/15853.misc b/changelog.d/15853.misc
deleted file mode 100644
index 3e9516b1ad..0000000000
--- a/changelog.d/15853.misc
+++ /dev/null
@@ -1 +0,0 @@
-Add a timeout that aborts any Postgres statement taking more than 1 hour.
\ No newline at end of file
diff --git a/changelog.d/15854.misc b/changelog.d/15854.misc
deleted file mode 100644
index 8c940dd9c5..0000000000
--- a/changelog.d/15854.misc
+++ /dev/null
@@ -1 +0,0 @@
-Fix the `devenv up` configuration which was ignoring the config overrides.
\ No newline at end of file
diff --git a/changelog.d/15860.removal b/changelog.d/15860.removal
deleted file mode 100644
index 1993bf0299..0000000000
--- a/changelog.d/15860.removal
+++ /dev/null
@@ -1 +0,0 @@
-Remove deprecated `worker_replication_host`, `worker_replication_http_port` and `worker_replication_http_tls` configuration options.
diff --git a/changelog.d/15861.misc b/changelog.d/15861.misc
deleted file mode 100644
index 6f320eab81..0000000000
--- a/changelog.d/15861.misc
+++ /dev/null
@@ -1 +0,0 @@
-Optimised cleanup of old entries in device_lists_stream.
diff --git a/changelog.d/15862.bugfix b/changelog.d/15862.bugfix
deleted file mode 100644
index 8eb6aa9a7f..0000000000
--- a/changelog.d/15862.bugfix
+++ /dev/null
@@ -1,3 +0,0 @@
-Pin `pydantic` to ^=1.7.4 to avoid backwards-incompatible API changes from the 2.0.0 release.
-Resolves https://github.com/matrix-org/synapse/issues/15858.
-Contributed by @PaarthShah.
diff --git a/changelog.d/15872.doc b/changelog.d/15872.doc
deleted file mode 100644
index 1993bf0299..0000000000
--- a/changelog.d/15872.doc
+++ /dev/null
@@ -1 +0,0 @@
-Remove deprecated `worker_replication_host`, `worker_replication_http_port` and `worker_replication_http_tls` configuration options.
diff --git a/changelog.d/15874.misc b/changelog.d/15874.misc
deleted file mode 100644
index 0d434bef5d..0000000000
--- a/changelog.d/15874.misc
+++ /dev/null
@@ -1 +0,0 @@
-Updated the link in home page from https://matrix.org/docs/projects/try-matrix-now.html#clients to https://matrix.org/ecosystem/clients/.
diff --git a/changelog.d/15876.bugfix b/changelog.d/15876.bugfix
deleted file mode 100644
index 9dbae04c4f..0000000000
--- a/changelog.d/15876.bugfix
+++ /dev/null
@@ -1 +0,0 @@
-Correctly resize thumbnails with pillow version >=10.
diff --git a/changelog.d/15888.misc b/changelog.d/15888.misc
deleted file mode 100644
index 0e49ab23fe..0000000000
--- a/changelog.d/15888.misc
+++ /dev/null
@@ -1 +0,0 @@
-Add tracing to media `/upload` code paths.
diff --git a/changelog.d/15892.misc b/changelog.d/15892.misc
deleted file mode 100644
index e5a123d218..0000000000
--- a/changelog.d/15892.misc
+++ /dev/null
@@ -1 +0,0 @@
-Stop running sytest on buster/python3.7.
diff --git a/changelog.d/15893.misc b/changelog.d/15893.misc
deleted file mode 100644
index 656d73b231..0000000000
--- a/changelog.d/15893.misc
+++ /dev/null
@@ -1 +0,0 @@
-Drop Debian Buster since we no longer support Python 3.7.
diff --git a/changelog.d/15906.misc b/changelog.d/15906.misc
deleted file mode 100644
index b721b88d56..0000000000
--- a/changelog.d/15906.misc
+++ /dev/null
@@ -1 +0,0 @@
-Fix building rust with nightly rust compiler.
diff --git a/changelog.d/15907.misc b/changelog.d/15907.misc
deleted file mode 100644
index e0ecea6c2f..0000000000
--- a/changelog.d/15907.misc
+++ /dev/null
@@ -1 +0,0 @@
-Add foreign key constraint to `event_forward_extremities`.
diff --git a/changelog.d/15908.misc b/changelog.d/15908.misc
deleted file mode 100644
index 3ab8674e03..0000000000
--- a/changelog.d/15908.misc
+++ /dev/null
@@ -1 +0,0 @@
-Add `Server` to Access-Control-Expose-Headers header.
diff --git a/debian/changelog b/debian/changelog
index 0d9216bee8..763edb8ec2 100644
--- a/debian/changelog
+++ b/debian/changelog
@@ -1,3 +1,9 @@
+matrix-synapse-py3 (1.88.0~rc1) stable; urgency=medium
+
+  * New Synapse release 1.88.0rc1.
+
+ -- Synapse Packaging team <packages@matrix.org>  Tue, 11 Jul 2023 10:20:19 +0100
+
 matrix-synapse-py3 (1.87.0) stable; urgency=medium
 
   * New Synapse release 1.87.0.
diff --git a/pyproject.toml b/pyproject.toml
index fc1b8c0dad..b61b8b17ac 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -89,7 +89,7 @@ manifest-path = "rust/Cargo.toml"
 
 [tool.poetry]
 name = "matrix-synapse"
-version = "1.87.0"
+version = "1.88.0rc1"
 description = "Homeserver for the Matrix decentralised comms protocol"
 authors = ["Matrix.org Team and Contributors <packages@matrix.org>"]
 license = "Apache-2.0"