diff --git a/cert_service.opam b/cert_service.opam
index e69de29..d9aab65 100644
--- a/cert_service.opam
+++ b/cert_service.opam
@@ -0,0 +1,22 @@
+opam-version: "2.0"
+maintainer: "Reynir Björnsson <reynir@reynir.dk>"
+authors: ["Reynir Björnsson <reynir@reynir.dk>"]
+license: "ISC"
+
+depends: [
+  "ocaml"
+  "dune"
+  "extunix"
+  "x509"
+  "duration"
+  "ptime"
+  "asn1-combinators"
+  "lwt"
+  "bos"
+  "mirage-crypto-rng"
+]
+build: [
+  ["dune" "subst"] {pinned}
+  ["dune" "build" "-p" name "-j" jobs]
+]
+synopsis: "ACME-like certificate signing service for shell servers"