diff --git a/.travis/autobrew.py b/.travis/autobrew.py
index 1a477206..80d28a07 100644
--- a/.travis/autobrew.py
+++ b/.travis/autobrew.py
@@ -30,6 +30,7 @@ class Ocrmypdf < Formula
   depends_on "libjpeg"
   depends_on "webp"
   depends_on "little-cms2"
+  depends_on "zlib"
 
 ${resources}
   def install