diff --git a/packages/TCSLib/TCSLib.0.5/opam b/packages/TCSLib/TCSLib.0.5/opam
index 6ded7c81489e..cbbab657398f 100644
--- a/packages/TCSLib/TCSLib.0.5/opam
+++ b/packages/TCSLib/TCSLib.0.5/opam
@@ -27,6 +27,11 @@ build: [
   ]
 ]
 dev-repo: "git+https://github.com/tcsprojects/tcslib.git"
+x-maintenance-intent: ["(none)"]
+flags: deprecated
+post-messages: [
+  "TCSLib has been renamed to tcs-lib. Use the tcs-lib package instead."
+]
 url {
   src:
     "https://github.com/tcsprojects/tcslib/releases/download/v0.5/tcslib-0.5.tbz"
diff --git a/packages/tcs-lib/tcs-lib.0.6/opam b/packages/tcs-lib/tcs-lib.0.6/opam
new file mode 100644
index 000000000000..8ad89b2ea31c
--- /dev/null
+++ b/packages/tcs-lib/tcs-lib.0.6/opam
@@ -0,0 +1,39 @@
+opam-version: "2.0"
+synopsis: "A multi-purpose library for OCaml"
+description: "A multi-purpose library for OCaml."
+maintainer: ["Oliver Friedmann" "Martin Lange"]
+authors: ["Oliver Friedmann" "Martin Lange"]
+license: "BSD-3-clause"
+homepage: "https://github.com/tcsprojects/tcslib"
+bug-reports: "https://github.com/tcsprojects/tcslib/issues"
+depends: [
+  "ocaml" {>= "4.8"}
+  "dune" {>= "3.18"}
+  "num"
+  "odoc" {with-doc}
+]
+build: [
+  ["dune" "subst"] {dev}
+  [
+    "dune"
+    "build"
+    "-p"
+    name
+    "-j"
+    jobs
+    "@install"
+    "@runtest" {with-test}
+    "@doc" {with-doc}
+  ]
+]
+dev-repo: "git+https://github.com/tcsprojects/tcslib.git"
+x-maintenance-intent: ["(latest)"]
+url {
+  src:
+    "https://github.com/tcsprojects/tcslib/releases/download/v0.6/tcs-lib-0.6.tbz"
+  checksum: [
+    "sha256=0c18dd20e52b61b7cddd595369030819eccfa4ea73bfdbed9839815586628122"
+    "sha512=9f77a89114e7511efa7d40fe5464b318677e729c672bdfe7e461f38509eca2cffb9da912eef02158413525732b8fdcf5765491b29c2ee0d831118a365e1e77b1"
+  ]
+}
+x-commit-hash: "6778419cd98af92632fba9883a1bbc0f93c8deef"