diff --git a/CHANGES.md b/CHANGES.md
index dc6fa1779..9f6e29631 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -1,9 +1,9 @@
-Synapse 1.49.1 (2021-12-21)
+Synapse 1.49.2 (2021-12-21)
 ===========================
 
 This release fixes a regression introduced in Synapse 1.49.0 which could cause `/sync` requests to take significantly longer. This would particularly affect "initial" syncs for users participating in a large number of rooms, and in extreme cases, could make it impossible for such users to log in on a new client.
 
-**Note:** in line with our [deprecation policy](https://matrix-org.github.io/synapse/latest/deprecation_policy.html) for platform dependencies, this will be the last release to support Python 3.6 and PostgreSQL 9.6, both of which have now reached upstream end-of-life. Synapse will require Python 3.7+ and PostgreSQL 10.
+**Note:** in line with our [deprecation policy](https://matrix-org.github.io/synapse/latest/deprecation_policy.html) for platform dependencies, this will be the last release to support Python 3.6 and PostgreSQL 9.6, both of which have now reached upstream end-of-life. Synapse will require Python 3.7+ and PostgreSQL 10+.
 
 **Note:** We will also stop producing packages for Ubuntu 18.04 (Bionic Beaver) after this release, as it uses Python 3.6.
 
@@ -12,6 +12,17 @@ Bugfixes
 
 - Fix a performance regression in `/sync` handling, introduced in 1.49.0. ([\#11583](https://github.com/matrix-org/synapse/issues/11583))
 
+Internal Changes
+----------------
+
+- Work around a build problem on Debian Buster. ([\#11625](https://github.com/matrix-org/synapse/issues/11625))
+
+
+Synapse 1.49.1 (2021-12-21)
+===========================
+
+Not released due to problems building the debian packages.
+
 
 Synapse 1.49.0 (2021-12-14)
 ===========================
diff --git a/debian/changelog b/debian/changelog
index 61a1d003b..ebe3e0cbf 100644
--- a/debian/changelog
+++ b/debian/changelog
@@ -1,3 +1,9 @@
+matrix-synapse-py3 (1.49.2) stable; urgency=medium
+
+  * New synapse release 1.49.2.
+
+ -- Synapse Packaging team <packages@matrix.org>  Tue, 21 Dec 2021 17:31:03 +0000
+
 matrix-synapse-py3 (1.49.1) stable; urgency=medium
 
   * New synapse release 1.49.1.
diff --git a/synapse/__init__.py b/synapse/__init__.py
index d45e0f188..95a49c20b 100644
--- a/synapse/__init__.py
+++ b/synapse/__init__.py
@@ -47,7 +47,7 @@
 except ImportError:
     pass
 
-__version__ = "1.49.1"
+__version__ = "1.49.2"
 
 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 fe684f5b1..d07440191 100644
--- a/synapse/python_dependencies.py
+++ b/synapse/python_dependencies.py
@@ -50,7 +50,8 @@
 REQUIREMENTS = [
     # we use the TYPE_CHECKER.redefine method added in jsonschema 3.0.0
     "jsonschema>=3.0.0",
-    "frozendict>=1",
+    # frozendict 2.1.2 is broken on Debian 10: https://github.com/Marco-Sulla/python-frozendict/issues/41
+    "frozendict>=1,<2.1.2",
     "unpaddedbase64>=1.1.0",
     "canonicaljson>=1.4.0",
     # we use the type definitions added in signedjson 1.1.