Same problematic code exists in 1.0.0

Author: Leonidas-from-XIV

packages/pkcs11-driver/pkcs11-driver.1.0.0/opam

@@ -20,7 +20,7 @@ depends: [
   "ppx_deriving" { >= "4.0" }
   "ppx_deriving_yojson" { >= "3.0" }
   "yojson" {>= "1.6.0"}
-  "ocaml" {>= "4.04.0"}
+  "ocaml" {>= "4.04.0" & < "5.1"}
   "ounit" {with-test}
 ]
 conflicts: [