diff --git a/lib/build.ml b/lib/build.ml
index 67bc12ef..7778ceb3 100644
--- a/lib/build.ml
+++ b/lib/build.ml
@@ -15,6 +15,7 @@ module Spec = struct
   type opam_build = {
     revdep : package option;
     with_tests : bool;
+    lower_bounds : bool;
     upgrade_opam : bool [@default false];
   } [@@deriving to_yojson]
 
@@ -27,8 +28,8 @@ module Spec = struct
     ty : ty;
   }
 
-  let opam ?revdep ~platform ~with_tests ~upgrade_opam pkg =
-    let ty = `Opam (`Build { revdep; with_tests; upgrade_opam }, pkg) in
+  let opam ?revdep ~platform ~lower_bounds ~with_tests ~upgrade_opam pkg =
+    let ty = `Opam (`Build { revdep; lower_bounds; with_tests; upgrade_opam }, pkg) in
     { platform; ty }
 
   let pp_pkg ?revdep f pkg =
@@ -39,9 +40,10 @@ module Spec = struct
   let pp_ty f = function
     | `Opam (`List_revdeps, pkg) ->
         Fmt.pf f "list revdeps of %s" (OpamPackage.to_string pkg)
-    | `Opam (`Build { revdep; with_tests; upgrade_opam }, pkg) ->
+    | `Opam (`Build { revdep; lower_bounds; with_tests; upgrade_opam }, pkg) ->
       let action = if with_tests then "test" else "build" in
-      Fmt.pf f "%s %a%s" action (pp_pkg ?revdep) pkg
+      Fmt.pf f "%s %a%s%s" action (pp_pkg ?revdep) pkg
+        (if lower_bounds then ", lower-bounds" else "")
         (if upgrade_opam then ", using opam 2.1" else "")
 end
 
@@ -122,7 +124,7 @@ module Op = struct
       let base = Image.hash base in
       match ty with
       | `Opam (`List_revdeps, pkg) -> Opam_build.revdeps ~for_docker ~base ~variant ~pkg
-      | `Opam (`Build { revdep; with_tests; upgrade_opam }, pkg) -> Opam_build.spec ~for_docker ~upgrade_opam ~base ~variant ~revdep ~with_tests ~pkg
+      | `Opam (`Build { revdep; lower_bounds; with_tests; upgrade_opam }, pkg) -> Opam_build.spec ~for_docker ~upgrade_opam ~base ~variant ~revdep ~lower_bounds ~with_tests ~pkg
     in
     Current.Job.write job
       (Fmt.strf "@.\
diff --git a/lib/build.mli b/lib/build.mli
index 78f704d3..8b8c868e 100644
--- a/lib/build.mli
+++ b/lib/build.mli
@@ -4,6 +4,7 @@ module Spec : sig
   val opam :
     ?revdep:OpamPackage.t ->
     platform:Platform.t ->
+    lower_bounds:bool ->
     with_tests:bool ->
     upgrade_opam:bool ->
     OpamPackage.t ->
diff --git a/lib/opam_build.ml b/lib/opam_build.ml
index ff833e91..6f54b2cd 100644
--- a/lib/opam_build.ml
+++ b/lib/opam_build.ml
@@ -2,32 +2,36 @@ let download_cache = "opam-archives"
 let cache = [ Obuilder_spec.Cache.v download_cache ~target:"/home/opam/.opam/download-cache" ]
 let network = ["host"]
 
-let opam_install ~variant ~upgrade_opam ~pin ~with_tests ~pkg =
+let opam_upgrade_cmd = "sudo ln -f /usr/bin/opam-2.1 /usr/bin/opam && opam init --reinit -ni"
+
+let opam_install ~variant ~is_opam_2_1 ~pin ~lower_bounds ~with_tests ~pkg =
   let pkg = OpamPackage.to_string pkg in
+  let upgrade_opam = lower_bounds || is_opam_2_1 in
   let open Obuilder_spec in
-  let pin =
-    if pin then
-      let version =
-        let idx = String.index pkg '.' + 1 in
-        String.sub pkg idx (String.length pkg - idx)
-      in
-      [ run "opam pin add -k version -yn %s %s" pkg version ]
-    else
-      []
-  in
-  pin @ [
+  (if lower_bounds then
+     (if not is_opam_2_1 then [run "%s" opam_upgrade_cmd] else []) @
+     [
+       env "OPAMCRITERIA" "+removed,+count[version-lag,solution]";
+       env "OPAMEXTERNALSOLVER" "builtin-0install";
+     ]
+   else
+     []
+  ) @
+  (if pin then
+     let version =
+       let idx = String.index pkg '.' + 1 in
+       String.sub pkg idx (String.length pkg - idx)
+     in
+     [ run "opam pin add -k version -yn %s %s" pkg version ]
+   else
+     []
+  ) @ [
     run ~network "opam %s" (if upgrade_opam then "update --depexts" else "depext -yu");
     (* TODO: Replace by two calls to opam install + opam install -t using the OPAMDROPINSTALLEDPACKAGES feature *)
-    run ~cache ~network {|
-        opam remove -y %s && opam %s%s %s;
+    run ~cache ~network
+      {|opam remove -y %s && opam %s%s %s;
         res=$?;
-        test "$res" = 0 && exit 0;
-        if test "$res" = 60 && diff -q /usr/bin/opam /usr/bin/opam-2.0; then
-          sudo ln -f /usr/bin/opam-2.1 /usr/bin/opam && opam init --reinit -ni;
-          opam remove -y %s && opam install -vy%s %s%s;
-          exit 1;
-        fi;
-        test "$res" != 31 && exit 1;
+        test "$res" != 31 && exit "$res";
         export OPAMCLI=2.0;
         build_dir=$(opam var prefix)/.opam-switch/build;
         failed=$(ls "$build_dir");
@@ -38,7 +42,6 @@ let opam_install ~variant ~upgrade_opam ~pin ~with_tests ~pkg =
         done;
         exit 1|}
       pkg (if upgrade_opam then "install -vy" else "depext -ivy") (if with_tests then "t" else "") pkg
-      pkg (if with_tests then "t" else "") pkg (if with_tests then "" else " && opam reinstall -vyt "^pkg)
       (Variant.distribution variant)
   ]
 
@@ -73,19 +76,24 @@ let set_personality ~variant =
   else
     []
 
-let spec ~for_docker ~upgrade_opam ~base ~variant ~revdep ~with_tests ~pkg =
+let spec ~for_docker ~upgrade_opam ~base ~variant ~revdep ~lower_bounds ~with_tests ~pkg =
+  let opam_install = opam_install ~variant ~is_opam_2_1:upgrade_opam in
   let revdep = match revdep with
     | None -> []
-    | Some revdep -> opam_install ~variant ~upgrade_opam ~pin:false ~with_tests:false ~pkg:revdep
+    | Some revdep -> opam_install ~pin:false ~lower_bounds:false ~with_tests:false ~pkg:revdep
   and tests = match with_tests, revdep with
-    | true, None -> opam_install ~variant ~upgrade_opam ~pin:false ~with_tests:true ~pkg
-    | true, Some revdep -> opam_install ~variant ~upgrade_opam ~pin:false ~with_tests:true ~pkg:revdep
+    | true, None -> opam_install ~pin:false ~lower_bounds:false ~with_tests:true ~pkg
+    | true, Some revdep -> opam_install ~pin:false ~lower_bounds:false ~with_tests:true ~pkg:revdep
     | false, _ -> []
+  and lower_bounds = match lower_bounds with
+    | true -> opam_install ~pin:false ~lower_bounds:true ~with_tests:false ~pkg
+    | false -> []
   in
   Obuilder_spec.stage ~from:base (
     set_personality ~variant
     @ setup_repository ~variant ~for_docker ~upgrade_opam
-    @ opam_install ~variant ~upgrade_opam ~pin:true ~with_tests:false ~pkg
+    @ opam_install ~pin:true ~lower_bounds:false ~with_tests:false ~pkg
+    @ lower_bounds
     @ revdep
     @ tests
   )
diff --git a/lib/opam_build.mli b/lib/opam_build.mli
index 1527b37a..35586bb2 100644
--- a/lib/opam_build.mli
+++ b/lib/opam_build.mli
@@ -4,6 +4,7 @@ val spec :
   base:string ->
   variant:Variant.t ->
   revdep:OpamPackage.t option ->
+  lower_bounds:bool ->
   with_tests:bool ->
   pkg:OpamPackage.t ->
   Obuilder_spec.t
diff --git a/service/pipeline.ml b/service/pipeline.ml
index 3764a91c..2aa906e7 100644
--- a/service/pipeline.ml
+++ b/service/pipeline.ml
@@ -73,19 +73,25 @@ let dep_list_map (type a) (module M : Current_term.S.ORDERED with type t = a) ?c
 
 let build_spec ~platform ~upgrade_opam pkg =
   let+ pkg = pkg in
-  Build.Spec.opam ~platform ~with_tests:false ~upgrade_opam pkg
+  Build.Spec.opam ~platform ~lower_bounds:false ~with_tests:false ~upgrade_opam pkg
 
 let test_spec ~platform ~upgrade_opam ~after pkg =
   let+ _ = after
   and+ pkg = pkg
   in
-  Build.Spec.opam ~platform ~with_tests:true ~upgrade_opam pkg
+  Build.Spec.opam ~platform ~lower_bounds:false  ~with_tests:true ~upgrade_opam pkg
+
+let lower_bounds_spec ~platform ~upgrade_opam ~after pkg =
+  let+ _ = after
+  and+ pkg = pkg
+  in
+  Build.Spec.opam ~platform ~lower_bounds:true ~with_tests:false ~upgrade_opam pkg
 
 let revdep_spec ~platform ~upgrade_opam ~revdep pkg =
   let+ revdep = revdep
   and+ pkg = pkg
   in
-  Build.Spec.opam ~platform ~with_tests:true ~revdep ~upgrade_opam pkg
+  Build.Spec.opam ~platform ~lower_bounds:false ~with_tests:true ~revdep ~upgrade_opam pkg
 
 let combine_revdeps revdeps =
   let map =
@@ -150,15 +156,24 @@ let build_with_cluster ~ocluster ~analysis ~lint ~master source =
           let spec = test_spec ~platform ~upgrade_opam pkg ~after:image in
           Build.v ocluster ~label:"test" ~base ~spec ~master source
         in
+        let lower_bounds_check =
+          let spec = lower_bounds_spec ~platform ~upgrade_opam pkg ~after:image in
+          Build.v ocluster ~label:"lower-bounds" ~base ~spec ~master source
+        in
         let+ pkg = pkg
         and+ build = Node.action `Built image
         and+ tests = Node.action `Built tests
+        and+ lower_bounds_check = Node.action `Built lower_bounds_check
         and+ revdeps =
           if revdeps then test_revdeps ~ocluster ~master ~base ~platform ~pkg source ~after:image
           else Current.return []
         in
         let label = OpamPackage.to_string pkg in
-        Node.actioned_branch ~label build (Node.leaf ~label:"tests" tests :: revdeps)
+        Node.actioned_branch ~label build (
+          Node.leaf ~label:"tests" tests ::
+          Node.leaf ~label:"lower-bounds" lower_bounds_check ::
+          revdeps
+        )
       )
     |> Current.map (Node.branch ~label)
     |> Current.collapse ~key:"platform" ~value:label ~input:analysis