diff --git a/HowtoGitit.md b/HowtoGitit.md
index ef3ee803..4c7fb737 100644
--- a/HowtoGitit.md
+++ b/HowtoGitit.md
@@ -10,7 +10,7 @@
 
 ### Manuellement
 
-    # apt install cabal-install ghc
+    # apt install cabal-install ghc zlib1g-dev
     # adduser gitit
     # sudo -ui gitit
     $ cabal update