diff --git a/src/plugins/loader-cache-state.test.ts b/src/plugins/loader-cache-state.test.ts
index 6ccce703899e..158b6cf23c1d 100644
--- a/src/plugins/loader-cache-state.test.ts
+++ b/src/plugins/loader-cache-state.test.ts
@@ -18,6 +18,18 @@ describe("PluginLoaderCacheState", () => {
     expect(cache.get("c")).toBe("charlie");
   });
 
+  it("bounds open-allowlist warning suppression by loader cache capacity", () => {
+    const cache = new PluginLoaderCacheState<string>(2);
+
+    cache.recordOpenAllowlistWarning("first");
+    cache.recordOpenAllowlistWarning("second");
+    cache.recordOpenAllowlistWarning("third");
+
+    expect(cache.hasOpenAllowlistWarning("first")).toBe(false);
+    expect(cache.hasOpenAllowlistWarning("second")).toBe(true);
+    expect(cache.hasOpenAllowlistWarning("third")).toBe(true);
+  });
+
   it("clears registry, in-flight, and warning state together", () => {
     const cache = new PluginLoaderCacheState<string>(2);
 
diff --git a/src/plugins/loader-cache-state.ts b/src/plugins/loader-cache-state.ts
index 97de1860e95e..f02c16e6c4c7 100644
--- a/src/plugins/loader-cache-state.ts
+++ b/src/plugins/loader-cache-state.ts
@@ -16,10 +16,11 @@ class PluginLoadReentryError extends Error {
 export class PluginLoaderCacheState<T> {
   readonly #registryCache: PluginLruCache<T>;
   readonly #inFlightLoads = new Set<string>();
-  readonly #openAllowlistWarningCache = new Set<string>();
+  readonly #openAllowlistWarningCache: PluginLruCache<true>;
 
   constructor(defaultMaxEntries: number) {
     this.#registryCache = new PluginLruCache<T>(defaultMaxEntries);
+    this.#openAllowlistWarningCache = new PluginLruCache<true>(defaultMaxEntries);
   }
 
   clear(): void {
@@ -57,10 +58,10 @@ export class PluginLoaderCacheState<T> {
   }
 
   hasOpenAllowlistWarning(cacheKey: string): boolean {
-    return this.#openAllowlistWarningCache.has(cacheKey);
+    return this.#openAllowlistWarningCache.get(cacheKey) === true;
   }
 
   recordOpenAllowlistWarning(cacheKey: string): void {
-    this.#openAllowlistWarningCache.add(cacheKey);
+    this.#openAllowlistWarningCache.set(cacheKey, true);
   }
 }