diff --git a/charts/matrix-stack/configs/synapse/synapse-04-homeserver-overrides.yaml.tpl b/charts/matrix-stack/configs/synapse/synapse-04-homeserver-overrides.yaml.tpl
index b7f97ab37..75ea37f1c 100644
--- a/charts/matrix-stack/configs/synapse/synapse-04-homeserver-overrides.yaml.tpl
+++ b/charts/matrix-stack/configs/synapse/synapse-04-homeserver-overrides.yaml.tpl
@@ -103,6 +103,7 @@ matrix_authentication_service:
                       )
                   ) }}
   endpoint: http://{{ $root.Release.Name }}-matrix-authentication-service.{{ $root.Release.Namespace }}.svc.{{ $root.Values.clusterDomain }}:8080/
+  force_http2: true
 {{- end }}
 
 {{- if or (include "element-io.matrix-authentication-service.readyToHandleAuth" (dict "root" $root)) $root.Values.matrixRTC.enabled $root.Values.hookshot.enabled }}
diff --git a/charts/matrix-stack/source/synapse.yaml.j2 b/charts/matrix-stack/source/synapse.yaml.j2
index a3a0048e2..f09712f33 100644
--- a/charts/matrix-stack/source/synapse.yaml.j2
+++ b/charts/matrix-stack/source/synapse.yaml.j2
@@ -87,7 +87,7 @@ logging:
   ## levelOverrides:
   ##   synapse.util.caches.lrucache: WARNING
   levelOverrides: {}
-{{- sub_schema_values.image(registry='oci.element.io', repository='synapse', tag='v1.150.0') }}
+{{- sub_schema_values.image(registry='oci.element.io', repository='synapse', tag='v1.151.0rc1') }}
 {{- sub_schema_values.extraVolumes("Synapse", with_context=true) }}
 {{- sub_schema_values.extraVolumeMounts("Synapse", with_context=true) }}
 {{- sub_schema_values.extraInitContainers("Synapse") }}
diff --git a/charts/matrix-stack/values.yaml b/charts/matrix-stack/values.yaml
index 67801cf8f..df715029f 100644
--- a/charts/matrix-stack/values.yaml
+++ b/charts/matrix-stack/values.yaml
@@ -4935,7 +4935,7 @@ synapse:
 
     ## The tag of the container image to use.
     ## One of tag or digest must be provided.
-    tag: "v1.150.0"
+    tag: "v1.151.0rc1"
 
     ## Container digest to use. Used to pull the image instead of the image tag if set
     ## The tag will still be set as the app.kubernetes.io/version label
diff --git a/newsfragments/1207.changed.1.md b/newsfragments/1207.changed.1.md
new file mode 100644
index 000000000..4921322b8
--- /dev/null
+++ b/newsfragments/1207.changed.1.md
@@ -0,0 +1,3 @@
+Use HTTP2 for Synapse to Matrix Authentication Service traffic.
+
+This reduces the overhead of token introspection, as Synapse will be able to use a single HTTP/2 connection to Matrix Authentication Service.
diff --git a/newsfragments/1207.changed.md b/newsfragments/1207.changed.md
new file mode 100644
index 000000000..e9acc61a6
--- /dev/null
+++ b/newsfragments/1207.changed.md
@@ -0,0 +1,9 @@
+Upgrade Synapse to v1.151.0.
+
+Highlights:
+- Add stable support for [MSC4284](https://github.com/matrix-org/matrix-spec-proposals/pull/4284) Policy Servers
+- Update and stabilize support for [MSC2666](https://github.com/matrix-org/matrix-spec-proposals/pull/2666): Get rooms in common with another user
+- Allow Synapse to start up even when discovery fails for an OpenID Connect provider
+
+Full Changelogs:
+- [v1.151.0](https://github.com/element-hq/synapse/releases/tag/v1.151.0)