diff --git a/ouroboros-consensus-diffusion/changelog.d/20231129_105548_nick.frisby_ChainSync_future.md b/ouroboros-consensus-diffusion/changelog.d/20231129_105548_nick.frisby_ChainSync_future.md
new file mode 100644
index 0000000000..bbd432b4e0
--- /dev/null
+++ b/ouroboros-consensus-diffusion/changelog.d/20231129_105548_nick.frisby_ChainSync_future.md
@@ -0,0 +1,23 @@
+<!--
+A new scriv changelog fragment.
+
+Uncomment the section that is right (remove the HTML comment wrapper).
+-->
+
+<!--
+### Patch
+
+- A bullet item for the Patch category.
+
+-->
+<!--
+### Non-Breaking
+
+- A bullet item for the Non-Breaking category.
+
+-->
+
+### Breaking
+
+- Integrate the new `InFutureCheck` in the ChainSync client, which requires new
+  fields in `NodeKernalArgs`.
diff --git a/ouroboros-consensus/changelog.d/20231129_105543_nick.frisby_ChainSync_future.md b/ouroboros-consensus/changelog.d/20231129_105543_nick.frisby_ChainSync_future.md
new file mode 100644
index 0000000000..857ac638a7
--- /dev/null
+++ b/ouroboros-consensus/changelog.d/20231129_105543_nick.frisby_ChainSync_future.md
@@ -0,0 +1,24 @@
+<!--
+A new scriv changelog fragment.
+
+Uncomment the section that is right (remove the HTML comment wrapper).
+-->
+
+<!--
+### Patch
+
+- A bullet item for the Patch category.
+
+-->
+<!--
+### Non-Breaking
+
+- A bullet item for the Non-Breaking category.
+
+-->
+### Breaking
+
+- Added a new `InFutureCheck` to the ChainSync client, which requires
+  additional arguments to the 'chainSyncClient' definition. The node no longer
+  propagates headers/blocks from the future: a ChainSync client thread now
+  sleeps until the received header is no longer from the future.