diff --git a/make.sh b/make.sh
index 788289c5ed..af1411a8d3 100755
--- a/make.sh
+++ b/make.sh
@@ -8,7 +8,7 @@ opam_setup() {
   set -x
   opam init -y -a --bare $SANDBOXING # sandboxing is disabled in travis and docker
   opam update
-  opam switch -y create . --deps-only ocaml-variants.4.14.0+options ocaml-option-flambda --locked
+  opam switch -y create . --deps-only --packages=ocaml-variants.4.14.0+options,ocaml-option-flambda --locked
 }
 
 rule() {