diff --git a/packages/yojson-bench/yojson-bench.2.0.0/opam b/packages/yojson-bench/yojson-bench.2.0.0/opam
new file mode 100644
index 00000000000..63e2470e385
--- /dev/null
+++ b/packages/yojson-bench/yojson-bench.2.0.0/opam
@@ -0,0 +1,34 @@
+opam-version: "2.0"
+maintainer: ["paul-elliot@tarides.com" "nathan@tarides.com" "marek@tarides.com"]
+authors: ["Martin Jambon"]
+homepage: "https://github.com/ocaml-community/yojson"
+bug-reports: "https://github.com/ocaml-community/yojson/issues"
+dev-repo: "git+https://github.com/ocaml-community/yojson.git"
+doc: "https://ocaml-community.github.io/yojson/"
+license: "BSD-3-Clause"
+depends: [
+  "ocaml" {>= "4.08"}
+  "yojson" {= version}
+  "dune"
+  "core_bench" {>= "v0.14.0"}
+  "core" {>= "v0.14.0"}
+  "core_unix" {>= "v0.14.0"}
+]
+build: [
+  ["dune" "subst"] {pinned}
+  ["dune" "build" "-p" name "-j" jobs]
+]
+synopsis: "Run Yojson benchmarks"
+description: """\
+Yojson benchmarks require `Core_bench` which is not a dependency of Yojson,
+because it is not part of the regular installation/testing flow. This is solely
+meant for developers that are worried about performance changes in Yojson."""
+url {
+  src:
+    "https://github.com/ocaml-community/yojson/releases/download/2.0.0/yojson-2.0.0.tbz"
+  checksum: [
+    "sha256=ab5d863f7f951a8f7fb4a708399ca2da2cf139a5e0af7818145c20295420cb1a"
+    "sha512=3ea982dbeef7ec8da54d29124ddb8b86f90583eb96ed3947851cedec9e3d2d47b981e3465d41f2c94943e6865ba6a9a51c6f0252efa6df2386d398b679aae8f2"
+  ]
+}
+x-commit-hash: "9c5cee131ae0ec79713e62397076d597486844ed"
diff --git a/packages/yojson/yojson.2.0.0/opam b/packages/yojson/yojson.2.0.0/opam
new file mode 100644
index 00000000000..b096689a020
--- /dev/null
+++ b/packages/yojson/yojson.2.0.0/opam
@@ -0,0 +1,38 @@
+opam-version: "2.0"
+maintainer: ["nathan@cryptosense.com" "marek@xivilization.net"]
+authors: ["Martin Jambon"]
+homepage: "https://github.com/ocaml-community/yojson"
+bug-reports: "https://github.com/ocaml-community/yojson/issues"
+dev-repo: "git+https://github.com/ocaml-community/yojson.git"
+doc: "https://ocaml-community.github.io/yojson/"
+license: "BSD-3-Clause"
+build: [
+  ["dune" "subst"] {pinned}
+  ["dune" "build" "-p" name "-j" jobs]
+  ["dune" "runtest" "-p" name "-j" jobs] {with-test}
+  ["dune" "build" "@doc" "-p" name "-j" jobs] {with-doc}
+]
+depends: [
+  "ocaml" {>= "4.02.3"}
+  "dune"
+  "cppo" {build}
+  "alcotest" {with-test & >= "0.8.5"}
+  "odoc" {with-doc}
+  "seq" {>= "0.2.2"}
+]
+synopsis:
+  "Yojson is an optimized parsing and printing library for the JSON format"
+description: """
+Yojson is an optimized parsing and printing library for the JSON format.
+
+ydump is a pretty-printing command-line program provided with the
+yojson package."""
+url {
+  src:
+    "https://github.com/ocaml-community/yojson/releases/download/2.0.0/yojson-2.0.0.tbz"
+  checksum: [
+    "sha256=ab5d863f7f951a8f7fb4a708399ca2da2cf139a5e0af7818145c20295420cb1a"
+    "sha512=3ea982dbeef7ec8da54d29124ddb8b86f90583eb96ed3947851cedec9e3d2d47b981e3465d41f2c94943e6865ba6a9a51c6f0252efa6df2386d398b679aae8f2"
+  ]
+}
+x-commit-hash: "9c5cee131ae0ec79713e62397076d597486844ed"