diff --git a/dune-project b/dune-project
index 0c8ac2f..1a59bc8 100644
--- a/dune-project
+++ b/dune-project
@@ -1,4 +1,4 @@
-(lang dune 2.7)
+(lang dune 2.6)
 (name hacl_x25519)
 (generate_opam_files true)
 (source (github mirage/hacl))
diff --git a/freestanding/Makefile b/freestanding/Makefile
index 4b343c3..f411474 100644
--- a/freestanding/Makefile
+++ b/freestanding/Makefile
@@ -11,7 +11,7 @@ libhacl_x25519_freestanding_stubs.a:
 else
 CC ?= cc
 FREESTANDING_CFLAGS := $(shell PKG_CONFIG_PATH=$(PKG_CONFIG_PATH) pkg-config --cflags ocaml-freestanding)
-CFLAGS := -O3 -I../src/kremlin/include -I../src/kremlin/kremlib/dist/minimal -DKRML_HOST_TIME $(FREESTANDING_CFLAGS)
+CFLAGS := -O3 -I../src/kremlin/include -I../src/kremlin/kremlib/dist/minimal -I../src -DKRML_HOST_TIME $(FREESTANDING_CFLAGS)
 
 OBJS=hacl_x25519_stubs.o Hacl_Hash.o Hacl_Curve25519_51.o Hacl_Ed25519.o
 
diff --git a/freestanding/dune b/freestanding/dune
index b2edd6e..6bd6ef5 100644
--- a/freestanding/dune
+++ b/freestanding/dune
@@ -1,13 +1,8 @@
-(copy_files#
- (alias install)
- (files ../src/*.c))
-
-(copy_files#
- (alias install)
- (files ../src/*.h))
+(copy_files# ../src/*.c)
 
 (rule
- (deps Makefile)
+ (deps Makefile hacl_x25519_stubs.c Hacl_Hash.c Hacl_Curve25519_51.c
+   Hacl_Ed25519.c)
  (targets libhacl_x25519_freestanding_stubs.a)
  (action
   (no-infer
diff --git a/hacl_x25519.opam b/hacl_x25519.opam
index 92aacfe..95ae3ab 100644
--- a/hacl_x25519.opam
+++ b/hacl_x25519.opam
@@ -18,7 +18,7 @@ homepage: "https://github.com/mirage/hacl"
 doc: "https://mirage.github.io/hacl/doc"
 bug-reports: "https://github.com/mirage/hacl/issues"
 depends: [
-  "dune" {>= "2.7"}
+  "dune" {>= "2.6"}
   "benchmark" {with-test}
   "cstruct" {>= "3.5.0"}
   "eqaf"
@@ -30,7 +30,6 @@ depends: [
   "ppx_deriving_yojson" {with-test}
   "stdlib-shims" {with-test}
   "yojson" {with-test & >= "1.6.0"}
-  "odoc" {with-doc}
 ]
 depopts: ["ocaml-freestanding"]
 conflicts: [
@@ -38,7 +37,7 @@ conflicts: [
   "ocaml-freestanding" {< "0.6.0"}
 ]
 build: [
-  ["dune" "subst"] {dev}
+  ["dune" "subst"] {pinned}
   [
     "dune"
     "build"