diff --git a/README.md b/README.md
index 6a64e3d..8c8218d 100644
--- a/README.md
+++ b/README.md
@@ -24,7 +24,7 @@ To use the Intel MKL library:
 
 ```bash
 export  LACAML_LIBS="-L${MKLROOT}/lib/intel64 -Wl,--no-as-needed -lmkl_rt -lpthread -lm -ldl"
-opam install lacaml
+opam install --assume-depexts lacaml
 
 
 odoc-ltxhtml allows to embed equations in the documentation generated by Ocamldoc.
diff --git a/dune-project b/dune-project
index 06099ef..87191c8 100644
--- a/dune-project
+++ b/dune-project
@@ -28,6 +28,7 @@ in quantum chemistry.")
     (ocaml (>= 4.10))
     (dune  (>= 1.10))
     (camlp-streams (>= 5.0))
+    trexio
     lacaml
     getopt
     zarith
diff --git a/qcaml.opam b/qcaml.opam
index 8dad688..e7db983 100644
--- a/qcaml.opam
+++ b/qcaml.opam
@@ -21,6 +21,7 @@ depends: [
   "ocaml" {>= "4.10"}
   "dune" {>= "1.10"}
   "camlp-streams" {>= "5.0"}
+  "trexio"
   "lacaml"
   "getopt"
   "zarith"