diff --git a/memcache.inc b/memcache.inc
index f013d5b..95e0600 100644
--- a/memcache.inc
+++ b/memcache.inc
@@ -321,6 +321,8 @@ class MemCacheDrupal implements DrupalCacheInterface {
         // along with cache consistency.
         if ($length < $key_length) {
           $this->wildcard_flushes[$this->bin] = array();
+          $this->variable_set("cache_flush_$this->bin", time());
+          $this->cache_flush = time();
         }
         $key = substr($cid, 0, $key_length);
         $this->wildcard_flushes[$this->bin][$key][$length] = $_SERVER['REQUEST_TIME'];
diff --git a/tests/memcache.test b/tests/memcache.test
index b669eca..4b77164 100644
--- a/tests/memcache.test
+++ b/tests/memcache.test
@@ -335,6 +335,49 @@ class MemCacheClearCase extends MemcacheTestCase {
     $this->assertFalse($this->checkCacheExists('test_cid_2', $this->default_value), 'Cache item was cleared successfully.');
   }
 
+  /**
+   * Test different wildcards to verify the wildcard optimizations.
+   */
+  function testWildCardOptimizations() {
+
+    // Set and clear a cache with a short cid/wildcard.
+    cache_set('foo:1', $this->default_value, $this->default_bin);
+
+    $this->assertCacheExists(t('Foo cache was set.'), $this->default_value, 'foo:1');
+
+    cache_clear_all('foo', $this->default_bin, TRUE);
+    $this->assertCacheRemoved(t('Foo cache was invalidated.'), 'foo:1');
+
+    // Set additional longer caches.
+    cache_set('foobar', $this->default_value, $this->default_bin);
+    cache_set('foofoo', $this->default_value, $this->default_bin);
+
+    $this->assertCacheExists(t('Foobar cache set.'), $this->default_value, 'foobar');
+    $this->assertCacheExists(t('Foofoo cache set.'), $this->default_value, 'foofoo');
+
+    // Clear one of them with a wildcard and make sure the other one is still
+    // valid.
+    cache_clear_all('foobar', $this->default_bin, TRUE);
+    $this->assertCacheRemoved(t('Foobar cache invalidated.'), 'foobar');
+    $this->assertCacheExists(t('Foofoo cache still valid.'), $this->default_value, 'foofoo');
+
+    // Set and clear a cache with a different, equally short cid/wildcard.
+    cache_set('bar:1', $this->default_value, $this->default_bin);
+    $this->assertCacheExists(t('Bar cache was set.'), $this->default_value, 'bar:1');
+
+    cache_clear_all('bar', $this->default_bin, TRUE);
+    $this->assertCacheRemoved(t('Bar cache invalidated.'), 'bar:1');
+    $this->assertCacheExists(t('Foofoo cache still valid.'), $this->default_value, 'foofoo');
+
+    // Clear cache with an even shorter wildcard. This results in a full bin
+    // bin clear, all entries are marked invalid.
+    cache_set('bar:2', $this->default_value, $this->default_bin);
+    cache_clear_all('ba', $this->default_bin, TRUE);
+    $this->assertCacheRemoved(t('Bar:1 cache invalidated.'), 'bar:1');
+    $this->assertCacheRemoved(t('Bar:2 cache invalidated.'), 'bar:2');
+    $this->assertCacheRemoved(t('Foofoo cache invalidated.'), 'foofoo');
+  }
+
 
   /**
    * Test clearing using a cid.