diff --git a/build.ninja b/build.ninja
index 7f83e08..41243c7 100644
--- a/build.ninja
+++ b/build.ninja
@@ -28,7 +28,7 @@ rule compile_ocaml_dep
   pool = console
 
 rule compile_ocaml
-  command = scripts/compile_ocaml.sh  $target
+  command = cd ocaml ; ninja $target
   description = Compiling OCaml tools
   pool = console
 
@@ -68,9 +68,7 @@ build qmcchem.tar.gz: create_archive
 # Ocaml
 # -----
 
-build ocaml/generated.ninja : compile_ocaml_dep | EZFIO/Ocaml/ezfio.ml ocaml/Property.ml always
-build ocaml/qmcchem : compile_ocaml | ocaml/generated.ninja EZFIO/Ocaml/ezfio.ml 
-  target = qmcchem
+build ocaml/qmcchem : compile_ocaml | EZFIO/Ocaml/ezfio.ml ocaml/Property.ml 
 
 
 # Copy binaries in bin
diff --git a/scripts/compile_ocaml.sh b/scripts/compile_ocaml.sh
index 47045d8..77a2eef 100755
--- a/scripts/compile_ocaml.sh
+++ b/scripts/compile_ocaml.sh
@@ -8,4 +8,4 @@ fi
 
 cd ${QMCCHEM_PATH}/ocaml || exit -1
 
-ninja ${@} || exit -1
+exec ninja -f generated.ninja ${@} || exit -1