diff --git a/docs/config/meta.json b/docs/config/meta.json
index fbd7649bff..b7a9507a6d 100644
--- a/docs/config/meta.json
+++ b/docs/config/meta.json
@@ -1 +1 @@
-{"current_index": -37}
\ No newline at end of file
+{"current_index": -38}
diff --git a/docs/docs/changelog/v9-0.md b/docs/docs/changelog/v9-0.md
index 48074576da..16adac20c3 100644
--- a/docs/docs/changelog/v9-0.md
+++ b/docs/docs/changelog/v9-0.md
@@ -16,6 +16,6 @@ sidebar_position: -36
 
 * Removing support for Python 3.8, 3.9, 3.10. If you have downloaded/installed libeCalc manually, you will need to
 run with at least Python 3.11 from now on.
-* CONTROL_MARGIN and CONTROL_MARGIN_UNIT are required for compressors, except for simplified compressor trains.
-* CONTROL_MARGIN and CONTROL_MARGIN_UNIT not allowed for simplified compressor trains.
+* `CONTROL_MARGIN` and `CONTROL_MARGIN_UNIT` are required for compressors, except for simplified compressor trains.
+* `CONTROL_MARGIN` and `CONTROL_MARGIN_UNIT` not allowed for simplified compressor trains.
 * Simplified trains have to use generic charts. Single speed- and variable speed charts are not allowed.
\ No newline at end of file
diff --git a/docs/docs/changelog/v9-1.md b/docs/docs/changelog/v9-1.md
new file mode 100644
index 0000000000..e4ef1280c5
--- /dev/null
+++ b/docs/docs/changelog/v9-1.md
@@ -0,0 +1,25 @@
+---
+slug: "v9-1-release"
+title: "v9.1"
+authors: ecalc-team
+tags: [release, eCalc]
+sidebar_position: -37
+---
+
+# eCalc v9.1
+
+## Features
+
+* Upgrade NeqSim to v3.0.5 (from v2.5.21). This can affect fluid/EoS operations, but we have not registered any changes. There may be a small speed up in fluid operations.
+* `CONTROL_MARGIN` is no longer experimental!
+
+## Bug Fixes
+
+* Max Rate algorithm has been changed. The new version is a correct, but brute force algorithm. This will affect processing time negatively, but guarantee correctness.
+
+## Breaking changes
+
+
+## Documentation
+
+Compressor charts in documentation now shows surge line, control margin and stonewall for improved understanding.
diff --git a/docs/drafts/next.draft.md b/docs/drafts/next.draft.md
index 73cba64135..b0e28dff50 100644
--- a/docs/drafts/next.draft.md
+++ b/docs/drafts/next.draft.md
@@ -3,7 +3,7 @@ slug: "{{ version_slug }}"
 title: "{{ version_title }}"
 authors: ecalc-team
 tags: [release, eCalc]
-sidebar_position: -37
+sidebar_position: -38
 ---
 
 # eCalc {{ version }}