diff --git a/docker/Dockerfile-pgtests b/docker/Dockerfile-pgtests
index 92b804d193..b94484ea7f 100644
--- a/docker/Dockerfile-pgtests
+++ b/docker/Dockerfile-pgtests
@@ -1,6 +1,6 @@
 # Use the Sytest image that comes with a lot of the build dependencies
 # pre-installed
-FROM matrixdotorg/sytest:bionic
+FROM matrixdotorg/sytest:focal
 
 # The Sytest image doesn't come with python, so install that
 RUN apt-get update && apt-get -qq install -y python3 python3-dev python3-pip
diff --git a/docs/postgres.md b/docs/postgres.md
index e4861c1f12..0562021da5 100644
--- a/docs/postgres.md
+++ b/docs/postgres.md
@@ -1,6 +1,6 @@
 # Using Postgres
 
-Synapse supports PostgreSQL versions 9.6 or later.
+Synapse supports PostgreSQL versions 10 or later.
 
 ## Install postgres client libraries
 
diff --git a/synapse/storage/engines/postgres.py b/synapse/storage/engines/postgres.py
index 30f948a0f7..b3d71f661c 100644
--- a/synapse/storage/engines/postgres.py
+++ b/synapse/storage/engines/postgres.py
@@ -46,8 +46,8 @@ class PostgresEngine(BaseDatabaseEngine):
         self._version = db_conn.server_version
 
         # Are we on a supported PostgreSQL version?
-        if not allow_outdated_version and self._version < 90600:
-            raise RuntimeError("Synapse requires PostgreSQL 9.6 or above.")
+        if not allow_outdated_version and self._version < 100000:
+            raise RuntimeError("Synapse requires PostgreSQL 10 or above.")
 
         with db_conn.cursor() as txn:
             txn.execute("SHOW SERVER_ENCODING")