diff --git a/src/CacheMiddleware.php b/src/CacheMiddleware.php
index fa439c8..be52e1f 100644
--- a/src/CacheMiddleware.php
+++ b/src/CacheMiddleware.php
@@ -164,25 +164,28 @@ function (ResponseInterface $response) use ($request) {
                     return new FulfilledPromise(
                         $cacheEntry->getResponse()->withHeader(static::HEADER_CACHE_INFO, static::HEADER_CACHE_HIT)
                     );
-                } elseif ($staleResponse
-                    || ($maxStaleCache !== null && $cacheEntry->getStaleAge() <= $maxStaleCache)
+                } elseif ($cacheEntry->staleWhileValidate()
+                    && (($maxStaleCache === null) || ($staleResponse || $cacheEntry->getStaleAge() <= $maxStaleCache))
                 ) {
-                    // Staled cache!
+                    /*
+                     * The cached response indicated that it may be served stale while background revalidation (or fetch)
+                     * occurs, and the client did not limit maximum staleness. (https://tools.ietf.org/html/rfc5861#section-3)
+                     *
+                     * Return the cached, stale response; initiate deferred revalidation/re-fetch.
+                     */
+                    static::addReValidationRequest(
+                        static::getRequestWithReValidationHeader($request, $cacheEntry),
+                        $this->cacheStorage,
+                        $cacheEntry
+                    );
+
                     return new FulfilledPromise(
-                        $cacheEntry->getResponse()->withHeader(static::HEADER_CACHE_INFO, static::HEADER_CACHE_HIT)
+                        $cacheEntry->getResponse()
+                            ->withHeader(self::HEADER_CACHE_INFO, self::HEADER_CACHE_STALE)
                     );
-                } elseif ($cacheEntry->hasValidationInformation() && !$onlyFromCache) {
+                } elseif (($cacheEntry->staleWhileValidate() && $cacheEntry->getStaleAge() <= $maxStaleCache) || ($cacheEntry->hasValidationInformation() && !$onlyFromCache)) {
                     // Re-validation header
                     $request = static::getRequestWithReValidationHeader($request, $cacheEntry);
-
-                    if ($cacheEntry->staleWhileValidate()) {
-                        static::addReValidationRequest($request, $this->cacheStorage, $cacheEntry);
-
-                        return new FulfilledPromise(
-                            $cacheEntry->getResponse()
-                                ->withHeader(static::HEADER_CACHE_INFO, static::HEADER_CACHE_STALE)
-                        );
-                    }
                 }
             } else {
                 $cacheEntry = null;
diff --git a/tests/RequestCacheControlTest.php b/tests/RequestCacheControlTest.php
index 5dbdcc9..247e94e 100644
--- a/tests/RequestCacheControlTest.php
+++ b/tests/RequestCacheControlTest.php
@@ -42,6 +42,11 @@ protected function setUp(): void
                         (new Response())
                             ->withAddedHeader('Cache-Control', 'max-age=3')
                     );
+                case '/1s-stale-while-revalidate':
+                    return new FulfilledPromise(
+                        (new Response())
+                            ->withAddedHeader('Cache-Control', 'max-age=1, stale-while-revalidate=3')
+                    );
             }
 
             throw new \InvalidArgumentException();
@@ -162,6 +167,41 @@ public function testMaxStaleHeader()
             CacheMiddleware::HEADER_CACHE_MISS,
             $response->getHeaderLine(CacheMiddleware::HEADER_CACHE_INFO)
         );
+
+        $response = $this->client->get('http://test.com/1s-stale-while-revalidate', [
+            'headers' => [
+                'Cache-Control' => 'max-stale',
+            ]
+        ]);
+        $this->assertEquals(
+            CacheMiddleware::HEADER_CACHE_MISS,
+            $response->getHeaderLine(CacheMiddleware::HEADER_CACHE_INFO)
+        );
+
+        sleep(2);
+
+        $response = $this->client->get('http://test.com/1s-stale-while-revalidate', [
+            'headers' => [
+                'Cache-Control' => 'max-stale=1',
+            ]
+        ]);
+        $this->assertEquals(
+            CacheMiddleware::HEADER_CACHE_STALE,
+            $response->getHeaderLine(CacheMiddleware::HEADER_CACHE_INFO)
+        );
+
+        sleep(1);
+
+        $response = $this->client->get('http://test.com/1s-stale-while-revalidate', [
+            'headers' => [
+                'Cache-Control' => 'max-stale=1',
+            ]
+        ]);
+        $this->assertEquals(
+            CacheMiddleware::HEADER_CACHE_MISS,
+            $response->getHeaderLine(CacheMiddleware::HEADER_CACHE_INFO)
+        );
+
     }
 
     public function testMinFreshHeader()
diff --git a/tests/ResponseCacheControlTest.php b/tests/ResponseCacheControlTest.php
index 79e3353..fe62810 100644
--- a/tests/ResponseCacheControlTest.php
+++ b/tests/ResponseCacheControlTest.php
@@ -30,7 +30,7 @@ protected function setUp(): void
                 case '/2s-complex':
                     return new FulfilledPromise(
                         (new Response())
-                            ->withAddedHeader('Cache-Control', 'invalid-token="yes", max-age=2, stale-while-revalidate=60')
+                            ->withAddedHeader('Cache-Control', 'invalid-token="yes", max-age=2, stale-while-revalidate=3')
                     );
                 case '/no-store':
                     return new FulfilledPromise(
@@ -91,6 +91,11 @@ public function testMaxAgeComplexHeader()
 
         sleep(3);
 
+        $response = $this->client->get('http://test.com/2s-complex');
+        $this->assertEquals(CacheMiddleware::HEADER_CACHE_STALE, $response->getHeaderLine(CacheMiddleware::HEADER_CACHE_INFO));
+
+        sleep(5);
+
         $response = $this->client->get('http://test.com/2s-complex');
         $this->assertEquals(CacheMiddleware::HEADER_CACHE_MISS, $response->getHeaderLine(CacheMiddleware::HEADER_CACHE_INFO));
     }