diff --git a/composer.json b/composer.json
index 1204abf..8227c05 100644
--- a/composer.json
+++ b/composer.json
@@ -25,6 +25,10 @@
         "php": ">=5.4",
         "bshaffer/oauth2-server-php": "v1.5"
     },
+    "suggest": {
+        "mongodb/mongo-php-driver": "Required to use the Mongo storage engine",
+        "predis/predis": "Required to use the Redis storage engine",
+    }
     "autoload": {
         "psr-4": {
             "Pickles\\" : "src/"