diff --git a/.changeset/wild-areas-lick.md b/.changeset/wild-areas-lick.md
new file mode 100644
index 000000000..3653c9b3d
--- /dev/null
+++ b/.changeset/wild-areas-lick.md
@@ -0,0 +1,7 @@
+---
+'mermaid': patch
+---
+
+fix(timeline): fix loading `leftMargin` from config
+
+The `timeline.leftMargin` config value should now correctly control the size of the left margin, instead of being ignored.
diff --git a/packages/mermaid/src/diagrams/timeline/timelineRenderer.ts b/packages/mermaid/src/diagrams/timeline/timelineRenderer.ts
index 7f406b589..a0063a5f0 100644
--- a/packages/mermaid/src/diagrams/timeline/timelineRenderer.ts
+++ b/packages/mermaid/src/diagrams/timeline/timelineRenderer.ts
@@ -28,8 +28,7 @@ interface TimelineTask {
 export const draw = function (text: string, id: string, version: string, diagObj: Diagram) {
   //1. Fetch the configuration
   const conf = getConfig();
-  // @ts-expect-error - wrong config?
-  const LEFT_MARGIN = conf.leftMargin ?? 50;
+  const LEFT_MARGIN = conf.timeline?.leftMargin ?? 50;
 
   log.debug('timeline', diagObj.db);