@@ -3,6 +3,7 @@ import { WorkerPoolManager } from "@pierre/diffs/worker";
 import DiffsWorker from "@pierre/diffs/worker/worker.js?worker";
 import * as Schema from "effect/Schema";
 import { useEffect, useState, useSyncExternalStore, type ReactNode } from "react";
+import { useStableCallback } from "../hooks/useStableCallback";
 import { useTheme } from "../hooks/useTheme";
 import { resolveDiffThemeName, type DiffThemeName } from "../lib/diffRendering";
 import { PREFERRED_HIGHLIGHTER } from "../lib/syntaxHighlighting";
@@ -18,11 +19,11 @@ export class DiffWorkerError extends Schema.TaggedError<DiffWorkerError>()("Diff
 }
 
 const DIFF_WORKER_IDLE_TTL_MS = 30_000;
-const DIFF_WORKER_POOL_SIZE = (() => {
+function resolveDiffWorkerPoolSize() {
   const cores =
     typeof navigator === "undefined" ? 4 : Math.max(1, navigator.hardwareConcurrency || 4);
   return Math.max(2, Math.min(6, Math.floor(cores / 2)));
-})();
+}
 let sharedWorkerPool:
   | {
       readonly pool: WorkerPoolManager;
@@ -127,21 +128,24 @@ function DiffWorkerReady({ children }: { children?: ReactNode }) {
 export function DiffWorkerPoolProvider({ children }: { children?: ReactNode }) {
   const { resolvedTheme } = useTheme();
   const diffThemeName = resolveDiffThemeName(resolvedTheme);
+  const [workerPoolSize] = useState(resolveDiffWorkerPoolSize);
+  // A new subscribe identity makes React release and reacquire the shared pool on every render.
+  const subscribe = useStableCallback((onStoreChange: () => void) => {
+    if (typeof window === "undefined") return () => {};
+    const entry = acquireDiffWorkerPool(diffThemeName, workerPoolSize);
+    onStoreChange();
+    return () => {
+      entry.consumers -= 1;
+      if (entry.consumers !== 0) return;
+      entry.idleTimer = setTimeout(() => {
+        entry.idleTimer = undefined;
+        entry.pool.terminate();
+        if (sharedWorkerPool === entry) sharedWorkerPool = undefined;
+      }, DIFF_WORKER_IDLE_TTL_MS);
+    };
+  });
   const workerPool = useSyncExternalStore(
-    (onStoreChange) => {
-      if (typeof window === "undefined") return () => {};
-      const entry = acquireDiffWorkerPool(diffThemeName, DIFF_WORKER_POOL_SIZE);
-      onStoreChange();
-      return () => {
-        entry.consumers -= 1;
-        if (entry.consumers !== 0) return;
-        entry.idleTimer = setTimeout(() => {
-          entry.idleTimer = undefined;
-          entry.pool.terminate();
-          if (sharedWorkerPool === entry) sharedWorkerPool = undefined;
-        }, DIFF_WORKER_IDLE_TTL_MS);
-      };
-    },
+    subscribe,
     () => sharedWorkerPool?.pool,
     () => undefined,
   );