diff --git a/packages/cohttp-lwt-unix/cohttp-lwt-unix.0.99.0/opam b/packages/cohttp-lwt-unix/cohttp-lwt-unix.0.99.0/opam
index 2b053f7e208b..8045b111f27d 100644
--- a/packages/cohttp-lwt-unix/cohttp-lwt-unix.0.99.0/opam
+++ b/packages/cohttp-lwt-unix/cohttp-lwt-unix.0.99.0/opam
@@ -22,7 +22,7 @@ build: [
 depends: [
   "ocaml" {>= "4.03.0"}
   "jbuilder" {build & >= "1.0+beta10"}
-  "conduit-lwt-unix"
+  "conduit-lwt-unix" {< "2.0.0"}
   "cmdliner"
   "logs"
   "fmt"
diff --git a/packages/cohttp-lwt-unix/cohttp-lwt-unix.1.0.0/opam b/packages/cohttp-lwt-unix/cohttp-lwt-unix.1.0.0/opam
index f213ff1a7759..5df172eaed84 100644
--- a/packages/cohttp-lwt-unix/cohttp-lwt-unix.1.0.0/opam
+++ b/packages/cohttp-lwt-unix/cohttp-lwt-unix.1.0.0/opam
@@ -22,7 +22,7 @@ build: [
 depends: [
   "ocaml" {>= "4.03.0"}
   "jbuilder" {build & >= "1.0+beta10"}
-  "conduit-lwt-unix"
+  "conduit-lwt-unix" {< "2.0.0"}
   "cmdliner"
   "magic-mime"
   "logs"
diff --git a/packages/cohttp-lwt-unix/cohttp-lwt-unix.1.0.2/opam b/packages/cohttp-lwt-unix/cohttp-lwt-unix.1.0.2/opam
index 80d68ad95e7d..618af1e44fd0 100644
--- a/packages/cohttp-lwt-unix/cohttp-lwt-unix.1.0.2/opam
+++ b/packages/cohttp-lwt-unix/cohttp-lwt-unix.1.0.2/opam
@@ -21,7 +21,7 @@ build: [
 depends: [
   "ocaml" {>= "4.03.0"}
   "jbuilder" {build & >= "1.0+beta10"}
-  "conduit-lwt-unix" {>= "1.0.3"}
+  "conduit-lwt-unix" {>= "1.0.3" & < "2.0.0"}
   "cmdliner"
   "magic-mime"
   "logs"
diff --git a/packages/cohttp-lwt-unix/cohttp-lwt-unix.1.1.1/opam b/packages/cohttp-lwt-unix/cohttp-lwt-unix.1.1.1/opam
index 43a42f1939a8..4abb286264e1 100644
--- a/packages/cohttp-lwt-unix/cohttp-lwt-unix.1.1.1/opam
+++ b/packages/cohttp-lwt-unix/cohttp-lwt-unix.1.1.1/opam
@@ -16,12 +16,12 @@ bug-reports: "https://github.com/mirage/ocaml-cohttp/issues"
 depends: [
   "ocaml" {>= "4.03.0"}
   "dune" {>= "1.1.0"}
-  "conduit-lwt-unix" {>= "1.0.3"}
+  "conduit-lwt-unix" {>= "1.0.3" & < "2.0.0"}
   "cmdliner"
   "magic-mime"
   "logs"
   "fmt" {>= "0.8.2"}
-  "cohttp-lwt" {="1.1.1"}
+  "cohttp-lwt" {= "1.1.1"}
   "lwt" {>= "3.0.0"}
   "base-unix"
   "ounit" {with-test}
diff --git a/packages/cohttp-lwt-unix/cohttp-lwt-unix.1.2.0/opam b/packages/cohttp-lwt-unix/cohttp-lwt-unix.1.2.0/opam
index fa770504bcff..36a6a88ce175 100644
--- a/packages/cohttp-lwt-unix/cohttp-lwt-unix.1.2.0/opam
+++ b/packages/cohttp-lwt-unix/cohttp-lwt-unix.1.2.0/opam
@@ -43,12 +43,12 @@ bug-reports: "https://github.com/mirage/ocaml-cohttp/issues"
 depends: [
   "ocaml" {>= "4.04.1"}
   "dune" {>= "1.1.0"}
-  "conduit-lwt-unix" {>= "1.0.3"}
+  "conduit-lwt-unix" {>= "1.0.3" & < "2.0.0"}
   "cmdliner"
   "magic-mime"
   "logs"
   "fmt" {>= "0.8.2"}
-  "cohttp-lwt" {="1.2.0"}
+  "cohttp-lwt" {= "1.2.0"}
   "lwt" {>= "3.0.0"}
   "base-unix"
   "ounit" {with-test}
diff --git a/packages/cohttp-lwt-unix/cohttp-lwt-unix.2.0.0/opam b/packages/cohttp-lwt-unix/cohttp-lwt-unix.2.0.0/opam
index 538c4e4cb2f8..18d26f750436 100644
--- a/packages/cohttp-lwt-unix/cohttp-lwt-unix.2.0.0/opam
+++ b/packages/cohttp-lwt-unix/cohttp-lwt-unix.2.0.0/opam
@@ -27,7 +27,7 @@ bug-reports: "https://github.com/mirage/ocaml-cohttp/issues"
 depends: [
   "ocaml" {>= "4.04.1"}
   "dune" {>= "1.1.0"}
-  "conduit-lwt-unix" {>= "1.0.3"}
+  "conduit-lwt-unix" {>= "1.0.3" & < "2.0.0"}
   "cmdliner"
   "magic-mime"
   "logs"
diff --git a/packages/cohttp-lwt-unix/cohttp-lwt-unix.2.1.3/opam b/packages/cohttp-lwt-unix/cohttp-lwt-unix.2.1.3/opam
index 883458ee7a84..f519989ec62a 100644
--- a/packages/cohttp-lwt-unix/cohttp-lwt-unix.2.1.3/opam
+++ b/packages/cohttp-lwt-unix/cohttp-lwt-unix.2.1.3/opam
@@ -27,7 +27,7 @@ bug-reports: "https://github.com/mirage/ocaml-cohttp/issues"
 depends: [
   "ocaml" {>= "4.04.1"}
   "dune" {>= "1.1.0"}
-  "conduit-lwt-unix" {>= "1.0.3"}
+  "conduit-lwt-unix" {>= "1.0.3" & < "2.0.0"}
   "cmdliner"
   "magic-mime"
   "logs"
diff --git a/packages/cohttp-lwt-unix/cohttp-lwt-unix.2.2.0/opam b/packages/cohttp-lwt-unix/cohttp-lwt-unix.2.2.0/opam
index e77527559bd5..4b3d7b3cb8e5 100644
--- a/packages/cohttp-lwt-unix/cohttp-lwt-unix.2.2.0/opam
+++ b/packages/cohttp-lwt-unix/cohttp-lwt-unix.2.2.0/opam
@@ -27,12 +27,12 @@ bug-reports: "https://github.com/mirage/ocaml-cohttp/issues"
 depends: [
   "ocaml" {>= "4.04.1"}
   "dune" {>= "1.1.0"}
-  "conduit-lwt-unix" {>= "1.0.3"}
+  "conduit-lwt-unix" {>= "1.0.3" & < "2.0.0"}
   "cmdliner"
   "magic-mime"
   "logs"
   "fmt" {>= "0.8.2"}
-  "cohttp-lwt" {=version}
+  "cohttp-lwt" {= version}
   "lwt" {>= "3.0.0"}
   "base-unix"
   "ounit" {with-test}
diff --git a/packages/conduit-async/conduit-async.2.0.0/opam b/packages/conduit-async/conduit-async.2.0.0/opam
new file mode 100644
index 000000000000..f6117bee53c3
--- /dev/null
+++ b/packages/conduit-async/conduit-async.2.0.0/opam
@@ -0,0 +1,37 @@
+opam-version: "2.0"
+maintainer: "anil@recoil.org"
+authors: [
+  "Anil Madhavapeddy" "Thomas Leonard" "Thomas Gazagnaire" "Rudi Grinberg"
+]
+license: "ISC"
+tags: "org:mirage"
+homepage: "https://github.com/mirage/ocaml-conduit"
+bug-reports: "https://github.com/mirage/ocaml-conduit/issues"
+depends: [
+  "ocaml" {>= "4.03.0"}
+  "dune"
+  "core"
+  "ppx_sexp_conv" {>="v0.9.0"}
+  "sexplib"
+  "conduit" {=version}
+  "async" {>= "v0.10.0"}
+  "ipaddr" {>= "3.0.0"}
+]
+depopts: ["async_ssl"]
+conflicts: [
+  "async_ssl" {< "v0.9.0"}
+]
+build: [
+  ["dune" "subst"] {pinned}
+  ["dune" "build" "-p" name "-j" jobs]
+]
+dev-repo: "git+https://github.com/mirage/ocaml-conduit.git"
+synopsis: "A network connection establishment library for Async"
+url {
+  src:
+    "https://github.com/mirage/ocaml-conduit/releases/download/v2.0.0/conduit-v2.0.0.tbz"
+  checksum: [
+    "sha256=d973a5c3b49b2529d50016daa9cc9c35413c75f1d9c62f363ae416e51e3a8aa5"
+    "sha512=ae80a1f0593d8a8fef9c5f7d794f2312f9665459ebbc94f68c957cedaf93100320f9e8f373af95d4b9c34780b34744683ab08c5544f1f8efc355e557f6c9ad9d"
+  ]
+}
diff --git a/packages/conduit-lwt-unix/conduit-lwt-unix.2.0.0/opam b/packages/conduit-lwt-unix/conduit-lwt-unix.2.0.0/opam
new file mode 100644
index 000000000000..a60fbf603060
--- /dev/null
+++ b/packages/conduit-lwt-unix/conduit-lwt-unix.2.0.0/opam
@@ -0,0 +1,39 @@
+opam-version: "2.0"
+maintainer: "anil@recoil.org"
+authors: [
+  "Anil Madhavapeddy" "Thomas Leonard" "Thomas Gazagnaire" "Rudi Grinberg"
+]
+license: "ISC"
+tags: "org:mirage"
+homepage: "https://github.com/mirage/ocaml-conduit"
+bug-reports: "https://github.com/mirage/ocaml-conduit/issues"
+depends: [
+  "ocaml" {>= "4.03.0"}
+  "dune"
+  "base-unix"
+  "ppx_sexp_conv" {>="v0.9.0"}
+  "conduit-lwt" {=version}
+  "lwt" {>= "3.0.0"}
+  "uri" {>= "1.9.4"}
+  "ipaddr" {>= "4.0.0"}
+  "ipaddr-sexp"
+]
+depopts: ["tls" "lwt_ssl" "launchd"]
+conflicts: [
+  "tls" {< "0.8.0"}
+  "ssl" {< "0.5.9"}
+]
+build: [
+  ["dune" "subst"] {pinned}
+  ["dune" "build" "-p" name "-j" jobs]
+]
+dev-repo: "git+https://github.com/mirage/ocaml-conduit.git"
+synopsis: "A network connection establishment library for Lwt_unix"
+url {
+  src:
+    "https://github.com/mirage/ocaml-conduit/releases/download/v2.0.0/conduit-v2.0.0.tbz"
+  checksum: [
+    "sha256=d973a5c3b49b2529d50016daa9cc9c35413c75f1d9c62f363ae416e51e3a8aa5"
+    "sha512=ae80a1f0593d8a8fef9c5f7d794f2312f9665459ebbc94f68c957cedaf93100320f9e8f373af95d4b9c34780b34744683ab08c5544f1f8efc355e557f6c9ad9d"
+  ]
+}
diff --git a/packages/conduit-lwt/conduit-lwt.2.0.0/opam b/packages/conduit-lwt/conduit-lwt.2.0.0/opam
new file mode 100644
index 000000000000..6e0e18e640d0
--- /dev/null
+++ b/packages/conduit-lwt/conduit-lwt.2.0.0/opam
@@ -0,0 +1,32 @@
+opam-version: "2.0"
+maintainer: "anil@recoil.org"
+authors: [
+  "Anil Madhavapeddy" "Thomas Leonard" "Thomas Gazagnaire" "Rudi Grinberg"
+]
+license: "ISC"
+tags: "org:mirage"
+homepage: "https://github.com/mirage/ocaml-conduit"
+bug-reports: "https://github.com/mirage/ocaml-conduit/issues"
+depends: [
+  "ocaml" {>= "4.03.0"}
+  "dune"
+  "base-unix"
+  "ppx_sexp_conv" {>="v0.9.0"}
+  "sexplib"
+  "conduit" {=version}
+  "lwt" {>= "3.0.0"}
+]
+build: [
+  ["dune" "subst"] {pinned}
+  ["dune" "build" "-p" name "-j" jobs]
+]
+dev-repo: "git+https://github.com/mirage/ocaml-conduit.git"
+synopsis: "A portable network connection establishment library using Lwt"
+url {
+  src:
+    "https://github.com/mirage/ocaml-conduit/releases/download/v2.0.0/conduit-v2.0.0.tbz"
+  checksum: [
+    "sha256=d973a5c3b49b2529d50016daa9cc9c35413c75f1d9c62f363ae416e51e3a8aa5"
+    "sha512=ae80a1f0593d8a8fef9c5f7d794f2312f9665459ebbc94f68c957cedaf93100320f9e8f373af95d4b9c34780b34744683ab08c5544f1f8efc355e557f6c9ad9d"
+  ]
+}
diff --git a/packages/conduit-mirage/conduit-mirage.2.0.0/opam b/packages/conduit-mirage/conduit-mirage.2.0.0/opam
new file mode 100644
index 000000000000..b2c6fc655c7b
--- /dev/null
+++ b/packages/conduit-mirage/conduit-mirage.2.0.0/opam
@@ -0,0 +1,49 @@
+opam-version: "2.0"
+maintainer: "anil@recoil.org"
+authors: ["Anil Madhavapeddy" "Thomas Leonard" "Thomas Gazagnaire"]
+license: "ISC"
+tags: "org:mirage"
+homepage: "https://github.com/mirage/ocaml-conduit"
+bug-reports: "https://github.com/mirage/ocaml-conduit/issues"
+depends: [
+  "ocaml" {>= "4.03.0"}
+  "dune"
+  "ppx_sexp_conv" {>="v0.9.0"}
+  "sexplib"
+  "cstruct" {>= "3.0.0"}
+  "mirage-stack-lwt" {>= "1.3.0"}
+  "mirage-time-lwt" {>= "1.1.0"}
+  "mirage-flow-lwt" {>= "1.2.0"}
+  "mirage-random" {>= "1.2.0"}
+  "dns-client" {>= "4.0.0"}
+  "conduit-lwt"
+  "vchan" {>= "3.0.0"}
+  "xenstore"
+  "tls" {>= "0.8.0"}
+  "ipaddr" {>= "3.0.0"}
+  "ipaddr-sexp"
+
+  #these are required for tls.mirage, which conduit-mirage depends on
+  "mirage-kv-lwt" {>= "2.0.0"}
+  "mirage-clock" {>= "2.0.0"}
+  "ptime"
+]
+conflicts: [
+  "mirage-conduit"
+]
+
+build: [
+  ["dune" "subst"] {pinned}
+  ["dune" "build" "-p" name "-j" jobs]
+  ["dune" "runtest" "-p" name] {with-test}
+]
+dev-repo: "git+https://github.com/mirage/ocaml-conduit.git"
+synopsis: "A network connection establishment library for MirageOS"
+url {
+  src:
+    "https://github.com/mirage/ocaml-conduit/releases/download/v2.0.0/conduit-v2.0.0.tbz"
+  checksum: [
+    "sha256=d973a5c3b49b2529d50016daa9cc9c35413c75f1d9c62f363ae416e51e3a8aa5"
+    "sha512=ae80a1f0593d8a8fef9c5f7d794f2312f9665459ebbc94f68c957cedaf93100320f9e8f373af95d4b9c34780b34744683ab08c5544f1f8efc355e557f6c9ad9d"
+  ]
+}
diff --git a/packages/conduit/conduit.2.0.0/opam b/packages/conduit/conduit.2.0.0/opam
new file mode 100644
index 000000000000..0bc41b5f00f4
--- /dev/null
+++ b/packages/conduit/conduit.2.0.0/opam
@@ -0,0 +1,56 @@
+opam-version: "2.0"
+maintainer: "anil@recoil.org"
+authors: [
+  "Anil Madhavapeddy" "Thomas Leonard" "Thomas Gazagnaire" "Rudi Grinberg"
+]
+license: "ISC"
+tags: "org:mirage"
+homepage: "https://github.com/mirage/ocaml-conduit"
+doc: "https://mirage.github.io/ocaml-conduit/"
+bug-reports: "https://github.com/mirage/ocaml-conduit/issues"
+depends: [
+  "ocaml" {>= "4.03.0"}
+  "dune"
+  "ppx_sexp_conv" {>="v0.9.0"}
+  "sexplib"
+  "astring"
+  "uri"
+  "logs" {>= "0.5.0"}
+  "ipaddr" {>= "4.0.0"}
+  "ipaddr-sexp"
+]
+build: [
+  ["dune" "subst"] {pinned}
+  ["dune" "build" "-p" name "-j" jobs]
+]
+dev-repo: "git+https://github.com/mirage/ocaml-conduit.git"
+synopsis: "A network connection establishment library"
+description: """
+The `conduit` library takes care of establishing and listening for 
+TCP and SSL/TLS connections for the Lwt and Async libraries.
+
+The reason this library exists is to provide a degree of abstraction
+from the precise SSL library used, since there are a variety of ways
+to bind to a library (e.g. the C FFI, or the Ctypes library), as well
+as well as which library is used (just OpenSSL for now).
+
+By default, OpenSSL is used as the preferred connection library, but
+you can force the use of the pure OCaml TLS stack by setting the
+environment variable `CONDUIT_TLS=native` when starting your program.
+
+The useful opam packages available that extend this library are:
+
+- `conduit`: the main `Conduit` module
+- `conduit-lwt`: the portable Lwt implementation
+- `conduit-lwt-unix`: the Lwt/Unix implementation
+- `conduit-async` the Jane Street Async implementation
+- `conduit-mirage`: the MirageOS compatible implementation
+"""
+url {
+  src:
+    "https://github.com/mirage/ocaml-conduit/releases/download/v2.0.0/conduit-v2.0.0.tbz"
+  checksum: [
+    "sha256=d973a5c3b49b2529d50016daa9cc9c35413c75f1d9c62f363ae416e51e3a8aa5"
+    "sha512=ae80a1f0593d8a8fef9c5f7d794f2312f9665459ebbc94f68c957cedaf93100320f9e8f373af95d4b9c34780b34744683ab08c5544f1f8efc355e557f6c9ad9d"
+  ]
+}
diff --git a/packages/github-hooks-unix/github-hooks-unix.0.2.0/opam b/packages/github-hooks-unix/github-hooks-unix.0.2.0/opam
index ad3ac38baae1..9df1ff0ff13f 100644
--- a/packages/github-hooks-unix/github-hooks-unix.0.2.0/opam
+++ b/packages/github-hooks-unix/github-hooks-unix.0.2.0/opam
@@ -23,7 +23,7 @@ depends: [
   "ocaml" {>= "4.02.0"}
   "jbuilder" {build & >= "1.0+beta9"}
   "github-unix" {>= "3.0.1"}
-  "conduit-lwt-unix" {>= "1.0.0"}
+  "conduit-lwt-unix" {>= "1.0.0" & <"2.0.0"}
   "github-hooks" {>= "0.2.0"}
   "cohttp-lwt-unix" {>= "0.99.0"}
 ]
diff --git a/packages/github-hooks-unix/github-hooks-unix.0.4.0/opam b/packages/github-hooks-unix/github-hooks-unix.0.4.0/opam
index e2f6a05cc331..aa3191df9362 100644
--- a/packages/github-hooks-unix/github-hooks-unix.0.4.0/opam
+++ b/packages/github-hooks-unix/github-hooks-unix.0.4.0/opam
@@ -45,7 +45,7 @@ depends: [
   "ocaml" {>= "4.02.0"}
   "dune"
   "github-unix" {>= "3.0.1"}
-  "conduit-lwt-unix" {>= "1.0.0"}
+  "conduit-lwt-unix" {>= "1.0.0" & <"2.0.0"}
   "github-hooks" {>= "0.3.0"}
   "cohttp-lwt-unix" {>= "0.99.0"}
 ]
@@ -58,4 +58,4 @@ url {
   src:
     "https://github.com/dsheets/ocaml-github-hooks/releases/download/0.4.0/github-hooks-0.4.0.tbz"
   checksum: "md5=a38ffb298e3efeebf683106f37f4cb7d"
-}
\ No newline at end of file
+}
diff --git a/packages/github-hooks/github-hooks.0.3.0/opam b/packages/github-hooks/github-hooks.0.3.0/opam
index 8b88b55c242c..403483e085ed 100644
--- a/packages/github-hooks/github-hooks.0.3.0/opam
+++ b/packages/github-hooks/github-hooks.0.3.0/opam
@@ -26,6 +26,7 @@ depends: [
   "logs"
   "lwt" {< "4.0.0"}
   "cohttp-lwt" {>= "0.99.0"}
+  "conduit-lwt" {<"1.5.0"}
   "github" {>= "3.0.1"}
   "nocrypto"
   "cstruct"
diff --git a/packages/github-hooks/github-hooks.0.4.0/opam b/packages/github-hooks/github-hooks.0.4.0/opam
index 3d9b2a45c5c6..c85ab85b1084 100644
--- a/packages/github-hooks/github-hooks.0.4.0/opam
+++ b/packages/github-hooks/github-hooks.0.4.0/opam
@@ -48,6 +48,7 @@ depends: [
   "logs"
   "lwt"
   "cohttp-lwt" {>= "0.99.0"}
+  "conduit-lwt" {<"1.5.0"}
   "github" {>= "3.0.1"}
   "nocrypto"
   "cstruct"
@@ -62,4 +63,4 @@ url {
   src:
     "https://github.com/dsheets/ocaml-github-hooks/releases/download/0.4.0/github-hooks-0.4.0.tbz"
   checksum: "md5=a38ffb298e3efeebf683106f37f4cb7d"
-}
\ No newline at end of file
+}
diff --git a/packages/hiredis/hiredis.0.4/opam b/packages/hiredis/hiredis.0.4/opam
index 846c4dd1079f..dd2316f89d2f 100644
--- a/packages/hiredis/hiredis.0.4/opam
+++ b/packages/hiredis/hiredis.0.4/opam
@@ -17,7 +17,7 @@ depends: [
   "ocamlfind" {build}
   "ocamlbuild" {build}
   "topkg" {build}
-  "conduit-lwt-unix" {>= "1.0.0"}
+  "conduit-lwt-unix" {>= "1.0.0" & <"2.0.0"}
 ]
 synopsis: "Redis tools based on the Hiredis C library"
 description:
diff --git a/packages/hiredis/hiredis.0.6/opam b/packages/hiredis/hiredis.0.6/opam
index 3e0236c8739d..1a3be572c4eb 100644
--- a/packages/hiredis/hiredis.0.6/opam
+++ b/packages/hiredis/hiredis.0.6/opam
@@ -18,6 +18,7 @@ depends: [
   "ocamlbuild" {build}
   "topkg" {build}
   "lwt" {>= "3.3.0"}
+  "conduit-lwt-unix" {<"2.0.0"}
 ]
 synopsis: "Redis tools based on the Hiredis C library"
 description:
diff --git a/packages/hiredis/hiredis.0.7.1/opam b/packages/hiredis/hiredis.0.7.1/opam
index a194ab8e58bb..c9eb29264913 100644
--- a/packages/hiredis/hiredis.0.7.1/opam
+++ b/packages/hiredis/hiredis.0.7.1/opam
@@ -18,6 +18,7 @@ depends: [
   "ocamlbuild" {build}
   "topkg" {build}
   "lwt" {>= "3.3.0"}
+  "conduit-lwt-unix" {<"2.0.0"}
 ]
 synopsis: "Redis tools based on the Hiredis C library"
 description:
diff --git a/packages/hiredis/hiredis.0.8/opam b/packages/hiredis/hiredis.0.8/opam
index 3b9c5afefd5b..a6d52af307d1 100644
--- a/packages/hiredis/hiredis.0.8/opam
+++ b/packages/hiredis/hiredis.0.8/opam
@@ -15,6 +15,7 @@ depends: [
   "jbuilder" {build}
   "lwt" {>= "3.3.0"}
   "hiredis-value" {>= "0.8"}
+  "conduit-lwt-unix" {<"2.0.0"}
 ]
 synopsis: "Redis tools based on the Hiredis C library"
 description:
diff --git a/packages/prof_spacetime/prof_spacetime.0.2.0/opam b/packages/prof_spacetime/prof_spacetime.0.2.0/opam
index 5358be71bca6..6787e18daf92 100644
--- a/packages/prof_spacetime/prof_spacetime.0.2.0/opam
+++ b/packages/prof_spacetime/prof_spacetime.0.2.0/opam
@@ -17,7 +17,7 @@ depends: [
   "cohttp" {>= "0.99.0" & < "1.0"}
   "cohttp-lwt-unix" {< "1.0"}
   "conduit"
-  "conduit-lwt-unix"
+  "conduit-lwt-unix" {< "2.0.0"}
   "yojson"
   "lwt"
   "lambda-term" {< "2.0"}
diff --git a/packages/prof_spacetime/prof_spacetime.0.3.0/opam b/packages/prof_spacetime/prof_spacetime.0.3.0/opam
index cc4c74d77dcf..6a9c65f660e5 100644
--- a/packages/prof_spacetime/prof_spacetime.0.3.0/opam
+++ b/packages/prof_spacetime/prof_spacetime.0.3.0/opam
@@ -12,7 +12,7 @@ depends: [
   "cohttp" {>= "1.0.0"}
   "cohttp-lwt-unix"
   "conduit"
-  "conduit-lwt-unix"
+  "conduit-lwt-unix" {< "2.0.0"}
   "yojson"
   "lwt"
   "lambda-term"
diff --git a/packages/resp-server/resp-server.0.2/opam b/packages/resp-server/resp-server.0.2/opam
index e606af3fc7e0..9f7ecf586dcf 100644
--- a/packages/resp-server/resp-server.0.2/opam
+++ b/packages/resp-server/resp-server.0.2/opam
@@ -12,7 +12,7 @@ depends: [
   "ocaml" {>= "4.05.0"}
   "jbuilder" {build}
   "hiredis" {<= "0.7"}
-  "conduit-lwt-unix" {>= "1.0"}
+  "conduit-lwt-unix" {>= "1.0" & <"2.0.0"}
 ]
 build: [
   ["jbuilder" "build" "-p" name]
diff --git a/packages/resp-server/resp-server.0.3/opam b/packages/resp-server/resp-server.0.3/opam
index bbd89d06bafe..50cdd1d83bb6 100644
--- a/packages/resp-server/resp-server.0.3/opam
+++ b/packages/resp-server/resp-server.0.3/opam
@@ -12,7 +12,7 @@ depends: [
   "ocaml" {>= "4.05.0"}
   "jbuilder" {build}
   "hiredis-value" {>= "0.8"}
-  "conduit-lwt-unix" {>= "1.0"}
+  "conduit-lwt-unix" {>= "1.0" & <"2.0.0"}
 ]
 build: [
   ["jbuilder" "build" "-p" name "-j" jobs]
diff --git a/packages/resp-server/resp-server.0.9.1/opam b/packages/resp-server/resp-server.0.9.1/opam
index ee6d31469f94..d84f2186fb26 100644
--- a/packages/resp-server/resp-server.0.9.1/opam
+++ b/packages/resp-server/resp-server.0.9.1/opam
@@ -12,6 +12,7 @@ depends:
     "dune"
     "resp" {>= "0.9.1"}
     "resp-client" {>= "0.9.1"}
+    "conduit-lwt-unix" {>="1.0.0" & <"2.0.0"}
 ]
 
 build:
diff --git a/packages/resp-server/resp-server.0.9/opam b/packages/resp-server/resp-server.0.9/opam
index f25e7e541705..b8a64de32b6b 100644
--- a/packages/resp-server/resp-server.0.9/opam
+++ b/packages/resp-server/resp-server.0.9/opam
@@ -12,6 +12,7 @@ depends:
     "dune"
     "resp" {>= "0.9"}
     "resp-client" {>= "0.9"}
+    "conduit-lwt-unix" {>="1.0.0" & <"2.0.0"}
 ]
 
 build: