diff --git a/.changeset/fix-ssr-getServerSnapshot.md b/.changeset/fix-ssr-getServerSnapshot.md
new file mode 100644
index 000000000..567b99d03
--- /dev/null
+++ b/.changeset/fix-ssr-getServerSnapshot.md
@@ -0,0 +1,5 @@
+---
+"@stackflow/plugin-history-sync": patch
+---
+
+Fix SSR compatibility by adding getServerSnapshot parameter to useSyncExternalStore. This resolves the "Missing getServerSnapshot, which is required for server-rendered content" error in SSR environments.
diff --git a/extensions/plugin-history-sync/src/historySyncPlugin.tsx b/extensions/plugin-history-sync/src/historySyncPlugin.tsx
index 2082dabb1..507473121 100644
--- a/extensions/plugin-history-sync/src/historySyncPlugin.tsx
+++ b/extensions/plugin-history-sync/src/historySyncPlugin.tsx
@@ -175,6 +175,7 @@ export function historySyncPlugin<
         const activityActivationCounts = useSyncExternalStore(
           subscribeActivityActivationCountsChange,
           getActivityActivationCounts,
+          getActivityActivationCounts,
         );
 
         return (