diff --git a/alcotest-async.opam b/alcotest-async.opam
index 765bed15..6a96e706 100644
--- a/alcotest-async.opam
+++ b/alcotest-async.opam
@@ -12,14 +12,15 @@ depends: [
   "dune" {>= "2.8"}
   "re" {with-test}
   "fmt" {with-test}
-  "cmdliner" {with-test & < "1.1.0"}
-  "core"
+  "cmdliner" {with-test & >= "1.1.0"}
+  "core" {>= "0.15.0"}
+  "core_unix" {>= "0.15.0"}
   "base"
   "async_kernel"
   "ocaml" {>= "4.05.0"}
   "alcotest" {= version}
-  "async_unix" {>= "v0.9.0"}
-  "core_kernel" {>= "v0.9.0"}
+  "async" {>= "v0.15.0"}
+  "async_unix" {>= "v0.15.0"}
   "odoc" {with-doc}
 ]
 build: [
diff --git a/alcotest-js.opam b/alcotest-js.opam
index dd366e2d..f4f47794 100644
--- a/alcotest-js.opam
+++ b/alcotest-js.opam
@@ -15,7 +15,7 @@ depends: [
   "alcotest" {= version}
   "js_of_ocaml-compiler" {>= "3.11.0"}
   "fmt" {with-test & >= "0.8.7"}
-  "cmdliner" {with-test & >= "1.0.0" & < "1.1.0"}
+  "cmdliner" {with-test & >= "1.1.0"}
   "odoc" {with-doc}
 ]
 build: [
diff --git a/alcotest-lwt.opam b/alcotest-lwt.opam
index dc41e298..a10e50fc 100644
--- a/alcotest-lwt.opam
+++ b/alcotest-lwt.opam
@@ -11,7 +11,7 @@ bug-reports: "https://github.com/mirage/alcotest/issues"
 depends: [
   "dune" {>= "2.8"}
   "re" {with-test}
-  "cmdliner" {with-test & < "1.1.0"}
+  "cmdliner" {with-test & >= "1.1.0"}
   "fmt"
   "ocaml" {>= "4.05.0"}
   "alcotest" {= version}
diff --git a/alcotest-mirage.opam b/alcotest-mirage.opam
index 128c80a5..f0dd459f 100644
--- a/alcotest-mirage.opam
+++ b/alcotest-mirage.opam
@@ -11,7 +11,7 @@ bug-reports: "https://github.com/mirage/alcotest/issues"
 depends: [
   "dune" {>= "2.8"}
   "re" {with-test}
-  "cmdliner" {with-test & < "1.1.0"}
+  "cmdliner" {with-test & >= "1.1.0"}
   "fmt"
   "ocaml" {>= "4.05.0"}
   "alcotest" {= version}
diff --git a/alcotest.opam b/alcotest.opam
index 27c67819..96403926 100644
--- a/alcotest.opam
+++ b/alcotest.opam
@@ -23,7 +23,7 @@ depends: [
   "ocaml" {>= "4.05.0"}
   "fmt" {>= "0.8.7"}
   "astring"
-  "cmdliner" {>= "1.0.0" & < "1.1.0"}
+  "cmdliner" {>= "1.1.0"}
   "re" {>= "1.7.2"}
   "stdlib-shims"
   "uutf" {>= "1.0.1"}
diff --git a/dune-project b/dune-project
index cce7c93b..958fdea8 100644
--- a/dune-project
+++ b/dune-project
@@ -27,7 +27,7 @@ tests to run.
   (ocaml (>= 4.05.0))
   (fmt (>= 0.8.7))
   astring
-  (cmdliner (and (>= 1.0.0) (< 1.1.0)))
+  (cmdliner (>= 1.1.0))
   (re (>= 1.7.2))
   stdlib-shims
   (uutf (>= 1.0.1))
@@ -44,8 +44,9 @@ tests to run.
  (depends
   (re :with-test)
   (fmt :with-test)
-  (cmdliner (and :with-test (< 1.1.0)))
+  (cmdliner (and :with-test (>= 1.1.0)))
   core
+  core_unix
   base
   async_kernel
   (ocaml (>= 4.05.0))
@@ -60,7 +61,7 @@ tests to run.
  (documentation "https://mirage.github.io/alcotest")
  (depends
   (re :with-test)
-  (cmdliner (and :with-test (< 1.1.0)))
+  (cmdliner (and :with-test (>= 1.1.0)))
   fmt
   (ocaml (>= 4.05.0))
   (alcotest (= :version))
@@ -74,7 +75,7 @@ tests to run.
  (documentation "https://mirage.github.io/alcotest")
  (depends
   (re :with-test)
-  (cmdliner (and :with-test (< 1.1.0)))
+  (cmdliner (and :with-test (>= 1.1.0)))
   fmt
   (ocaml (>= 4.05.0))
   (alcotest (= :version))
@@ -92,4 +93,4 @@ tests to run.
   (alcotest (= :version))
   (js_of_ocaml-compiler (>= 3.11.0))
   (fmt (and :with-test (>= 0.8.7)))
-  (cmdliner (and :with-test (>= 1.0.0) (< 1.1.0)))))
+  (cmdliner (and :with-test (>= 1.1.0)))))
diff --git a/src/alcotest-async/alcotest_async.ml b/src/alcotest-async/alcotest_async.ml
index 00b8e3cf..97ed6102 100644
--- a/src/alcotest-async/alcotest_async.ml
+++ b/src/alcotest-async/alcotest_async.ml
@@ -1,5 +1,4 @@
-open Core
-open Async_kernel
+open Async
 open Async_unix
 
 let run_test timeout name fn args =
@@ -8,7 +7,7 @@ let run_test timeout name fn args =
   | `Timeout ->
       Alcotest.fail
         (Printf.sprintf "%s timed out after %s" name
-           (Time.Span.to_string_hum timeout))
+           (Time_unix.Span.to_string_hum timeout))
 
 module Promise = struct
   include Deferred
@@ -25,7 +24,7 @@ module V1 = struct
 
   let test_case_sync n s f = test_case n s (fun x -> Deferred.return (f x))
 
-  let test_case ?(timeout = sec 2.) name s f =
+  let test_case ?(timeout = Time_unix.Span.of_sec 2.) name s f =
     test_case name s (run_test timeout name f)
 end
 
diff --git a/src/alcotest-async/alcotest_async_intf.ml b/src/alcotest-async/alcotest_async_intf.ml
index 24d7382c..f298f7c9 100644
--- a/src/alcotest-async/alcotest_async_intf.ml
+++ b/src/alcotest-async/alcotest_async_intf.ml
@@ -1,12 +1,12 @@
 module type V1 = sig
   include
-    Alcotest_engine.V1.Cli.S with type return = unit Async_kernel.Deferred.t
+    Alcotest_engine.V1.Cli.S with type return = unit Async.Deferred.t
 
   val test_case :
-    ?timeout:Core_kernel.Time.Span.t ->
+    ?timeout:Time_unix.Span.t ->
     string ->
     Alcotest.speed_level ->
-    ('a -> unit Async_kernel.Deferred.t) ->
+    ('a -> unit Async.Deferred.t) ->
     'a test_case
 
   val test_case_sync :
diff --git a/src/alcotest-async/dune b/src/alcotest-async/dune
index f69d6eff..9497c260 100644
--- a/src/alcotest-async/dune
+++ b/src/alcotest-async/dune
@@ -4,8 +4,9 @@
  (libraries
   alcotest.engine
   alcotest
+  async
   async_kernel
   async_unix
   base
   core
-  core_kernel))
+  core_unix.time_unix))