diff --git a/.travis.yml b/.travis.yml
index 3f08378a..416b0726 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -9,13 +9,11 @@ env:
    - PINS="conduit:. mirage-conduit:. conduit-async:. conduit-lwt:. conduit-lwt-unix:."
    - TESTS=true
  matrix:
-   - OCAML_VERSION=4.06.0 PACKAGE=conduit-lwt-unix DISTRO=debian-stable   DEPOPTS="ssl tls"
-   - OCAML_VERSION=4.05.0 PACKAGE=conduit-async    DISTRO=centos-7        DEPOPTS=async_ssl
-   - OCAML_VERSION=4.04.2 PACKAGE=conduit-lwt-unix DISTRO=alpine-3.6      DEPOPTS="ssl tls"
-   - OCAML_VERSION=4.04.1 PACKAGE=conduit-lwt-unix DISTRO=debian-stable   DEPOPTS="ssl tls"
-   - OCAML_VERSION=4.04.1 PACKAGE=conduit-async    DISTRO=debian-unstable DEPOPTS=async_ssl
-   - OCAML_VERSION=4.04.1 PACKAGE=conduit-async    DISTRO=ubuntu-17.04    DEPOPTS=async_ssl
-   - OCAML_VERSION=4.03.0 PACKAGE=conduit-lwt-unix DISTRO=debian-testing  DEPOPTS="ssl tls"
-   - OCAML_VERSION=4.03.0 PACKAGE=conduit-lwt-unix DISTRO=ubuntu-16.04    DEPOPTS="ssl tls"
-   - OCAML_VERSION=4.03.0 PACKAGE=conduit-lwt-unix DISTRO=centos-6        DEPOPTS="ssl tls"
-   - OCAML_VERSION=4.03.0 PACKAGE=conduit-lwt-unix DISTRO=fedora-26       DEPOPTS="ssl tls"
+   - OCAML_VERSION=4.07 PACKAGE=conduit-lwt-unix DISTRO=debian-stable   DEPOPTS="ssl tls"
+   - OCAML_VERSION=4.06 PACKAGE=conduit-lwt-unix DISTRO=debian-unstable DEPOPTS="ssl tls"
+   - OCAML_VERSION=4.05 PACKAGE=conduit-async    DISTRO=debian-unstable DEPOPTS=async_ssl
+   - OCAML_VERSION=4.04 PACKAGE=conduit-lwt-unix DISTRO=debian-testing  DEPOPTS="ssl tls"
+   - OCAML_VERSION=4.06 PACKAGE=conduit-async    DISTRO=centos          DEPOPTS=async_ssl
+   - OCAML_VERSION=4.06 PACKAGE=conduit-lwt-unix DISTRO=alpine          DEPOPTS="ssl tls"
+   - OCAML_VERSION=4.06 PACKAGE=conduit-async    DISTRO=ubuntu          DEPOPTS=async_ssl
+   - OCAML_VERSION=4.06 PACKAGE=conduit-lwt-unix DISTRO=fedora          DEPOPTS="ssl tls"
diff --git a/lwt-unix/jbuild b/lwt-unix/jbuild
index fdd18709..99cd9ed5 100644
--- a/lwt-unix/jbuild
+++ b/lwt-unix/jbuild
@@ -1,24 +1,46 @@
-(jbuild_version 1)
+(* -*- tuareg -*- *)
+
+let v ~launchd ~ssl ~tls () =
+  let launchd, launchd_d =
+    if launchd then "conduit_lwt_launchd_real", "launchd.lwt "
+    else "conduit_lwt_launchd_dummy", ""
+  in
+  let ssl, ssl_d =
+    if ssl then "conduit_lwt_unix_ssl_real", "lwt_ssl "
+    else "conduit_lwt_unix_ssl_dummy", ""
+  in
+  let tls, tls_d =
+    if tls then "conduit_lwt_tls_real", "tls.lwt "
+    else "conduit_lwt_tls_dummy", ""
+  in
+  Printf.sprintf {|
+(rule (copy %s.ml conduit_lwt_launchd.ml))
+(rule (copy %s.ml conduit_lwt_unix_ssl.ml))
+(rule (copy %s.ml conduit_lwt_tls.ml))
+(rule (copy %s.mli conduit_lwt_unix_ssl.mli))
+(rule (copy %s.mli conduit_lwt_tls.mli))
+
 (library
  ((name        conduit_lwt_unix)
   (public_name conduit-lwt-unix)
   (preprocess (pps (ppx_sexp_conv)))
   (wrapped false)
-  (modules (resolver_lwt_unix conduit_lwt_unix conduit_lwt_server conduit_lwt_tls conduit_lwt_unix_ssl conduit_lwt_launchd))
-  (libraries (conduit-lwt lwt.unix uri.services ipaddr.unix logs
-    (select conduit_lwt_launchd.ml from
-     (launchd.lwt  -> conduit_lwt_launchd_real.ml)
-     (!launchd.lwt -> conduit_lwt_launchd_dummy.ml))
-    (select conduit_lwt_unix_ssl.ml from
-     (lwt_ssl  -> conduit_lwt_unix_ssl_real.ml)
-     (!lwt_ssl -> conduit_lwt_unix_ssl_dummy.ml))
-    (select conduit_lwt_unix_ssl.mli from
-     (lwt_ssl  -> conduit_lwt_unix_ssl_real.mli)
-     (!lwt_ssl -> conduit_lwt_unix_ssl_dummy.mli))
-    (select conduit_lwt_tls.ml from
-     (tls.lwt  -> conduit_lwt_tls_real.ml)
-     (!tls.lwt -> conduit_lwt_tls_dummy.ml))
-    (select conduit_lwt_tls.mli from
-     (tls.lwt  -> conduit_lwt_tls_real.mli)
-     (!tls.lwt -> conduit_lwt_tls_dummy.mli))
-    ))))
+  (modules (resolver_lwt_unix conduit_lwt_unix conduit_lwt_server
+           conduit_lwt_tls conduit_lwt_unix_ssl conduit_lwt_launchd))
+  (libraries (conduit-lwt lwt.unix uri.services ipaddr.unix logs %s%s%s))))
+|} launchd ssl tls ssl tls launchd_d ssl_d tls_d
+
+let main () =
+  let is_installed s = Printf.kprintf Sys.command "ocamlfind query %s" s = 0 in
+  let launchd = is_installed "launchd.lwt" in
+  let ssl = is_installed "lwt_ssl" in
+  let tls = Sys.unix && is_installed "tls.lwt" in
+  Printf.printf
+    "Configuration\n\
+    \  launchd: %b\n\
+    \  ssl    : %b\n\
+    \  tls    : %b\n%!"
+    launchd ssl tls;
+  v ~launchd ~ssl ~tls ()
+
+let () = Jbuild_plugin.V1.send @@ main ()