diff --git a/haskell/Makefile b/haskell/Makefile
index fad89c87f..7ffb7990f 100644
--- a/haskell/Makefile
+++ b/haskell/Makefile
@@ -19,6 +19,7 @@ all: build pdf
 	
 build: $(BOOT_FILES)
 	cabal sandbox init
+	cabal install --dependencies-only
 	cabal configure
 	cabal build