diff --git a/.travis.yml b/.travis.yml
index c73cd77..4edcd67 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -26,10 +26,8 @@ before_install:
 install:
   # Install dependencies
   - opam pin add --no-action sequence .
-  - opam install oasis
-  - opam install --deps-only sequence
+  - opam install jbuilder base-bytes result
 script:
   - make build
   - opam install qcheck qtest
-  - ./configure --enable-tests
   - make test
diff --git a/Makefile b/Makefile
index 93b91f9..0d26fde 100644
--- a/Makefile
+++ b/Makefile
@@ -5,7 +5,7 @@ build:
 	jbuilder build @install
 
 test:
-	jbuilder runtest
+	jbuilder runtest --no-buffer
 
 clean:
 	jbuilder clean
diff --git a/qtest/Makefile b/qtest/Makefile
index 09e30e4..c8a9751 100644
--- a/qtest/Makefile
+++ b/qtest/Makefile
@@ -1,6 +1,6 @@
 
 QTEST_PREAMBLE=''
-DONTTEST=../src/sequenceLabels.ml
+DONTTEST=../src/sequenceLabels.ml ../src/mkflags.ml
 QTESTABLE=$(filter-out $(DONTTEST), \
 	$(wildcard ../src/*.ml) \
 	$(wildcard ../src/*.mli) \
diff --git a/qtest/jbuild b/qtest/jbuild
index 3b74acb..0843466 100644
--- a/qtest/jbuild
+++ b/qtest/jbuild
@@ -1,7 +1,7 @@
 
 (rule
   ((targets (run_qtest.ml))
-   (deps ((file Makefile)))
+   (deps ((file Makefile) )) ; (glob_files ../src/**/*.ml{,i})))
    (fallback)
    ;(libraries (qtest qcheck))
    (action
diff --git a/sequence.opam b/sequence.opam
index 45b873e..cb04bad 100644
--- a/sequence.opam
+++ b/sequence.opam
@@ -31,6 +31,6 @@ homepage: "https://github.com/c-cube/sequence/"
 depopts: [
   "base-bigarray"
 ]
-doc: "http://cedeela.fr/~simon/software/sequence/Sequence.html"
+doc: "https://c-cube.github.io/sequence/"
 bug-reports: "https://github.com/c-cube/sequence/issues"
 dev-repo: "https://github.com/c-cube/sequence.git"
diff --git a/src/bigarray/jbuild b/src/bigarray/jbuild
index e59b07f..f44100a 100644
--- a/src/bigarray/jbuild
+++ b/src/bigarray/jbuild
@@ -5,7 +5,6 @@
    (libraries (sequence bigarray))
    (wrapped false)
    (optional)
-   (flags (:standard -w +a-4-42-44-48-50-58-32-60@8 -w -33 -safe-string -color always))
-   (ocamlopt_flags (:standard -O3 -color always
-                    -unbox-closures -unbox-closures-factor 20))
+   (flags (:standard -w +a-4-42-44-48-50-58-32-60@8 -safe-string))
+   (ocamlopt_flags (:standard (:include ../flambda.flags)))
   ))
diff --git a/src/jbuild b/src/jbuild
index 981b07e..c20d7d9 100644
--- a/src/jbuild
+++ b/src/jbuild
@@ -1,11 +1,18 @@
+(rule
+  ((targets (flambda.flags))
+   (deps ((file mkflags.ml)))
+   (fallback)
+   (action
+     (run ocaml ./mkflags.ml))
+  ))
 
 (library
   ((name sequence)
    (public_name sequence)
    (wrapped false)
-   (flags (:standard -w +a-4-42-44-48-50-58-32-60@8 -safe-string -color always -nolabels))
-   (ocamlopt_flags (:standard -O3 -color always
-                    -unbox-closures -unbox-closures-factor 20))
+   (modules (Sequence SequenceLabels))
+   (flags (:standard -w +a-4-42-44-48-50-58-32-60@8 -safe-string -nolabels))
+   (ocamlopt_flags (:standard (:include flambda.flags)))
    (libraries (bytes result))
   ))
 
diff --git a/src/mkflags.ml b/src/mkflags.ml
new file mode 100644
index 0000000..e6edba0
--- /dev/null
+++ b/src/mkflags.ml
@@ -0,0 +1,14 @@
+
+ let () =
+   let major, minor =
+     Scanf.sscanf Sys.ocaml_version "%u.%u"
+       (fun major minor -> major, minor)
+   in
+   let after_4_3 = (major, minor) >= (4, 3) in
+   let flags_file = open_out "flambda.flags" in
+   if after_4_3 then (
+     output_string flags_file "(-O3 -unbox-closures -unbox-closures-factor 20 -color always)\n";
+   ) else (
+     output_string flags_file "()\n";
+   );
+   close_out flags_file