diff --git a/doc/install/fromsource.mdwn b/doc/install/fromsource.mdwn
index 1e96cce40e..733d736d02 100644
--- a/doc/install/fromsource.mdwn
+++ b/doc/install/fromsource.mdwn
@@ -43,7 +43,7 @@ git-annex, but it does not include the assistant or webapp.
 Inside the source tree, run:
 
 	cabal configure -f"-assistant -webapp -webdav -pairing -xmpp -dns"
-	cabal install --only-dependencies
+	cabal install -f"-assistant -webapp -webdav -pairing -xmpp -dns" --only-dependencies
 	cabal build
 	PATH=$HOME/bin:$PATH
 	cabal install --bindir=$HOME/bin