diff --git a/.travis.yml b/.travis.yml
index cf3e927..9cfe8ee 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -9,11 +9,11 @@ env:
   - DISTRO="ubuntu-16.04"
   - PACKAGE="gen" 
   matrix:
-  - OCAML_VERSION="4.02.3"
   - OCAML_VERSION="4.03"
-  - OCAML_VERSION="4.04"
+    #- OCAML_VERSION="4.04"
     #- PACKAGE="iter" OCAML_VERSION="4.05" EXTRA_DEPS="base-bigarray"
   - OCAML_VERSION="4.06"
   - OCAML_VERSION="4.07"
   - OCAML_VERSION="4.08"
-  - OCAML_VERSION="4.09"
+    #- OCAML_VERSION="4.09"
+  - OCAML_VERSION="4.10"
diff --git a/gen.opam b/gen.opam
index 091e157..c335a8a 100644
--- a/gen.opam
+++ b/gen.opam
@@ -15,6 +15,7 @@ depends: [
   "odoc" {with-doc}
   "qcheck" {with-test}
   "qtest" {with-test}
+  "ocaml" { >= "4.03.0" }
 ]
 tags: [ "gen" "iterator" "iter" "fold" ]
 homepage: "https://github.com/c-cube/gen/"