diff --git a/INSTALL b/INSTALL
index 244879d3..e7e5212d 100644
--- a/INSTALL
+++ b/INSTALL
@@ -35,6 +35,7 @@ General libraries:
  - libavl
  - MiniXML
  - gcrypt 1.2.0+
+ - zlib
  - libflac (optional - FLAC support)
  - taglib (optional - Musepack support)
  - libplist 0.16+ (optional - iTunes XML support)