diff --git a/src/dune_pkg/local_package.ml b/src/dune_pkg/local_package.ml
index 5a0c6ceecc7..ec6f0a61c92 100644
--- a/src/dune_pkg/local_package.ml
+++ b/src/dune_pkg/local_package.ml
@@ -1,12 +1,18 @@
 open Import
 module Package_constraint = Dune_lang.Package_constraint
 
+module Origin = struct
+  type t =
+    | Opam_file
+    | Pin_stanza
+end
+
 type pin =
   { loc : Loc.t
   ; version : Package_version.t
   ; url : Loc.t * OpamUrl.t
   ; name : Package_name.t
-  ; origin : [ `Dune | `Opam ]
+  ; origin : Origin.t
   }
 
 type pins = pin Package_name.Map.t
@@ -190,7 +196,7 @@ let of_package (t : Dune_lang.Package.t) =
             Package_version.of_opam_package_version (OpamPackage.version pkg)
           in
           let loc = Loc.in_file (Path.source file) in
-          name, { loc; version; url = loc, url; name; origin = `Opam })
+          name, { loc; version; url = loc, url; name; origin = Opam_file })
         |> Package_name.Map.of_list
       with
       | Ok x -> x
diff --git a/src/dune_pkg/local_package.mli b/src/dune_pkg/local_package.mli
index 72122d36533..41f0e5dd098 100644
--- a/src/dune_pkg/local_package.mli
+++ b/src/dune_pkg/local_package.mli
@@ -1,11 +1,17 @@
 open Import
 
+module Origin : sig
+  type t =
+    | Opam_file
+    | Pin_stanza
+end
+
 type pin =
   { loc : Loc.t
   ; version : Package_version.t
   ; url : Loc.t * OpamUrl.t
   ; name : Package_name.t
-  ; origin : [ `Dune | `Opam ]
+  ; origin : Origin.t
   }
 
 type pins = pin Package_name.Map.t
diff --git a/src/dune_pkg/pin.ml b/src/dune_pkg/pin.ml
index d0efe1cc135..38608937124 100644
--- a/src/dune_pkg/pin.ml
+++ b/src/dune_pkg/pin.ml
@@ -35,8 +35,8 @@ module DB = struct
       map =
         Package_name.Map.fold pins ~init:t.map ~f:(fun (pin : Local_package.pin) acc ->
           (match pin.origin with
-           | `Dune -> Code_error.raise "add_opam_pins: can only pin opam packages" []
-           | `Opam -> ());
+           | Pin_stanza -> Code_error.raise "add_opam_pins: can only pin opam packages" []
+           | Opam_file -> ());
           Package_name.Map.update acc pin.name ~f:(function
             | None -> Some (pin, t.context)
             | Some _ as x -> x))
@@ -50,7 +50,7 @@ module DB = struct
     ; map =
         Pin_stanza.Project.map pins
         |> Package_name.Map.map ~f:(fun (url, pkg) ->
-          let pkg = local_package_of_pin pkg ~url ~origin:`Dune in
+          let pkg = local_package_of_pin pkg ~url ~origin:Pin_stanza in
           pkg, context)
     }
   ;;
@@ -117,7 +117,7 @@ module DB = struct
       Dune_lang.Pin_stanza.Workspace.map pins
       |> String.Map.map ~f:(fun map ->
         Package_name.Map.map map ~f:(fun (url, package) ->
-          local_package_of_pin package ~url ~origin:`Dune))
+          local_package_of_pin package ~url ~origin:Pin_stanza))
     ;;
 
     let extract (t : t) ~names =
@@ -261,7 +261,7 @@ let resolve (t : DB.t) ~(scan_project : Scan_project.t)
           ; Stack.pp stack
           ]
   in
-  let opam_package stack (package : Local_package.pin) =
+  let pinned_via_opam stack (package : Local_package.pin) =
     let* resolved_package = Pinned_package.resolve_package package in
     resolve package.name resolved_package;
     Resolved_package.opam_file resolved_package
@@ -276,7 +276,7 @@ let resolve (t : DB.t) ~(scan_project : Scan_project.t)
         ; version
         ; name
         ; loc = package.loc
-        ; origin = `Opam
+        ; origin = Opam_file
         }
       in
       let stack = Stack.push stack package in
@@ -286,7 +286,7 @@ let resolve (t : DB.t) ~(scan_project : Scan_project.t)
     |> Fiber.parallel_iter ~f:(fun package ->
       Pinned_package.resolve_package package >>| resolve package.name)
   in
-  let dune_package packages (package : Local_package.pin) =
+  let pinned_via_dune packages (package : Local_package.pin) =
     match Package_name.Map.find packages package.name with
     | None ->
       User_error.raise
@@ -331,13 +331,13 @@ let resolve (t : DB.t) ~(scan_project : Scan_project.t)
     |> Fiber.parallel_iter ~f:(fun (package : Local_package.pin) ->
       let stack = Stack.push stack package in
       match package.origin with
-      | `Opam -> opam_package stack package
-      | `Dune ->
+      | Opam_file -> pinned_via_opam stack package
+      | Pin_stanza ->
         eval_url package.url
         >>= (function
-         | None -> opam_package stack package
+         | None -> pinned_via_opam stack package
          | Some (more_sources, packages) ->
-           dune_package packages package;
+           pinned_via_dune packages package;
            let more_sources = DB.add_opam_pins more_sources packages in
            loop stack more_sources))
   in