diff --git a/.changeset/finite-rate-limit-values.md b/.changeset/finite-rate-limit-values.md
new file mode 100644
index 00000000..1474980d
--- /dev/null
+++ b/.changeset/finite-rate-limit-values.md
@@ -0,0 +1,5 @@
+---
+"@chatcops/core": patch
+---
+
+Reject non-finite rate limit values during limiter creation.
diff --git a/packages/core/src/limits/rate-limit.ts b/packages/core/src/limits/rate-limit.ts
index 2f2aca3f..63e96a3c 100644
--- a/packages/core/src/limits/rate-limit.ts
+++ b/packages/core/src/limits/rate-limit.ts
@@ -56,8 +56,8 @@ export function createRateLimiter(
   rule: RateLimitRule,
   options: RateLimiterOptions = {}
 ): { check(key: string): Promise<RateLimitResult> } {
-  if (rule.limit <= 0) throw new Error('limit must be greater than 0');
-  if (rule.windowMs <= 0) throw new Error('windowMs must be greater than 0');
+  if (!Number.isFinite(rule.limit) || rule.limit <= 0) throw new Error('limit must be a finite number greater than 0');
+  if (!Number.isFinite(rule.windowMs) || rule.windowMs <= 0) throw new Error('windowMs must be a finite number greater than 0');
 
   const prefix = options.prefix ?? 'rl';
   const now = options.now ?? Date.now;
diff --git a/packages/core/tests/limits/rate-limit.test.ts b/packages/core/tests/limits/rate-limit.test.ts
index 3626bb36..876440bc 100644
--- a/packages/core/tests/limits/rate-limit.test.ts
+++ b/packages/core/tests/limits/rate-limit.test.ts
@@ -20,10 +20,14 @@ function countersOf(options?: Parameters<typeof memoryStorage>[0]): CounterStore
 describe('createRateLimiter', () => {
   it('throws on invalid rule', () => {
     const counters = countersOf();
-    expect(() => createRateLimiter(counters, { limit: 0, windowMs: 1000 })).toThrow('limit must be greater than 0');
-    expect(() => createRateLimiter(counters, { limit: -1, windowMs: 1000 })).toThrow('limit must be greater than 0');
-    expect(() => createRateLimiter(counters, { limit: 5, windowMs: 0 })).toThrow('windowMs must be greater than 0');
-    expect(() => createRateLimiter(counters, { limit: 5, windowMs: -1 })).toThrow('windowMs must be greater than 0');
+    expect(() => createRateLimiter(counters, { limit: 0, windowMs: 1000 })).toThrow('limit must be a finite number greater than 0');
+    expect(() => createRateLimiter(counters, { limit: -1, windowMs: 1000 })).toThrow('limit must be a finite number greater than 0');
+    expect(() => createRateLimiter(counters, { limit: Number.NaN, windowMs: 1000 })).toThrow('limit must be a finite number greater than 0');
+    expect(() => createRateLimiter(counters, { limit: Number.POSITIVE_INFINITY, windowMs: 1000 })).toThrow('limit must be a finite number greater than 0');
+    expect(() => createRateLimiter(counters, { limit: 5, windowMs: 0 })).toThrow('windowMs must be a finite number greater than 0');
+    expect(() => createRateLimiter(counters, { limit: 5, windowMs: -1 })).toThrow('windowMs must be a finite number greater than 0');
+    expect(() => createRateLimiter(counters, { limit: 5, windowMs: Number.NaN })).toThrow('windowMs must be a finite number greater than 0');
+    expect(() => createRateLimiter(counters, { limit: 5, windowMs: Number.POSITIVE_INFINITY })).toThrow('windowMs must be a finite number greater than 0');
   });
 
   it('allows exactly limit requests and blocks the next one', async () => {