diff --git a/.dockerignore b/.dockerignore
index 5c370aa..9ce487c 100644
--- a/.dockerignore
+++ b/.dockerignore
@@ -1,5 +1,6 @@
 .merlin
 node_modules/
+_build
 _opam
 *.byte
 *.native
diff --git a/docker/Dockerfile b/docker/Dockerfile
index bdc48f6..1977fc2 100644
--- a/docker/Dockerfile
+++ b/docker/Dockerfile
@@ -7,8 +7,11 @@ RUN sudo apk add --no-cache --update \
 
 WORKDIR /usr/app
 
-COPY . .
+COPY ./osnap.opam .
+
+RUN opam install . --with-test --yes && \
+  eval $(opam env)
 
-RUN opam install . --with-test --yes
+COPY . .
 
 RUN opam exec -- dune build -p osnap --profile=static
diff --git a/dune-project b/dune-project
index 43b9101..119d083 100644
--- a/dune-project
+++ b/dune-project
@@ -24,7 +24,6 @@
    (and
     (>= 4.14.0)
     (< 5.0.0)))
-  ocaml-option-flambda
   reason
   dune
   ocaml-lsp-server