diff --git a/composer.json b/composer.json
index 0eab7b1..4323240 100644
--- a/composer.json
+++ b/composer.json
@@ -12,7 +12,8 @@
     }
   ],
   "require": {
-    "php": ">=5.3.0"
+    "php": ">=5.3.0",
+    "ext-imap": "*"
   },
   "autoload": {
     "psr-0": {"Fetch": "src/"}