diff --git a/includes/cache.inc b/includes/cache.inc
index a19d3c3..41b5334 100644
--- a/includes/cache.inc
+++ b/includes/cache.inc
@@ -476,6 +476,9 @@ class DrupalDatabaseCache implements DrupalCacheInterface {
     }
     catch (Exception $e) {
       // The database may not be available, so we'll ignore cache_set requests.
+      // We can't use watchdog() because most sites will be using dblog, so we
+      // log directly to the PHP error log.
+      error_log("Unable to set an item in the cache: " . $e->getMessage());
     }
   }