diff --git a/lib/builder_web.ml b/lib/builder_web.ml
index 6c4f9a4..41dacbb 100644
--- a/lib/builder_web.ml
+++ b/lib/builder_web.ml
@@ -277,7 +277,7 @@ let routes t =
       | Ok (switch_left, _sha256_left), Ok (switch_right, _sha256_right) ->
         let switch_left = OpamFile.SwitchExport.read_from_string switch_left
         and switch_right = OpamFile.SwitchExport.read_from_string switch_right in
-        Opamdiff.compare (Opamdiff.packages switch_left) (Opamdiff.packages switch_right)
+        Opamdiff.compare switch_left switch_right
         |> Views.compare_opam build_left build_right
         |> Response.of_html
   in
diff --git a/lib/views.ml b/lib/views.ml
index 4192edd..49226be 100644
--- a/lib/views.ml
+++ b/lib/views.ml
@@ -226,7 +226,7 @@ let package_diffs diffs =
       ])
     diffs
 
-let compare_opam build_left build_right (same, version_diff, left, right) =
+let compare_opam build_left build_right (same, opam_diff, version_diff, left, right) =
   layout ~title:(Fmt.strf "Comparing opam switches between builds %a and %a"
                    Uuidm.pp build_left Uuidm.pp build_right)
     [
@@ -245,9 +245,13 @@ let compare_opam build_left build_right (same, version_diff, left, right) =
             [txtf "%d new packages installed" (OpamPackage.Set.cardinal right)]
         ];
         li [
-          a ~a:[a_href "#packages-diff"]
+          a ~a:[a_href "#packages-version-diff"]
             [txtf "%d packages with version changes" (List.length version_diff)]
         ];
+        li [
+          a ~a:[a_href "#packages-opam-diff"]
+            [txtf "%d packages with changes in their opam file" (OpamPackage.Set.cardinal opam_diff)]
+        ];
         li [
           a ~a:[a_href "#packages-unchanged"]
             [txtf "%d packages unchanged" (OpamPackage.Set.cardinal same)]
@@ -259,9 +263,12 @@ let compare_opam build_left build_right (same, version_diff, left, right) =
       h3 ~a:[a_id "packages-installed"]
         [txt "New packages installed"];
       code (packages right);
-      h3 ~a:[a_id "packages-diff"]
+      h3 ~a:[a_id "packages-version-diff"]
         [txt "Packages with version changes"];
       code (package_diffs version_diff);
+      h3 ~a:[a_id "packages-opam-diff"]
+        [txt "Packages with changes in their opam file"];
+      code (packages opam_diff);
       h3 ~a:[a_id "packages-unchanged"]
         [txt "Unchanged packages"];
       code (packages same);
diff --git a/opamdiff/opamdiff.ml b/opamdiff/opamdiff.ml
index f0d8a56..89b6f6c 100644
--- a/opamdiff/opamdiff.ml
+++ b/opamdiff/opamdiff.ml
@@ -24,6 +24,7 @@ let pp_version_diff ppf { name; version_left; version_right } =
     (OpamPackage.Version.to_string version_right)
 
 let compare left right =
+  let packages_left = packages left and packages_right = packages right in
   let module Set = OpamPackage.Set in
   let equal_name p1 p2 = OpamPackage.Name.equal p1.OpamPackage.name p2.OpamPackage.name in
   let diff l r =
@@ -31,10 +32,17 @@ let compare left right =
         not (Set.exists (equal_name p1) r))
       l
   in
-  let same = Set.inter left right
+  let same_version = Set.inter packages_left packages_right in
+  let (same, opam_diff) =
+    Set.partition
+      (fun p ->
+         let find = OpamPackage.Name.Map.find p.name in
+         let opam_left = find left.overlays and opam_right = find right.overlays in
+         OpamFile.OPAM.effectively_equal opam_left opam_right)
+      same_version
   and version_diff =
     List.filter_map (fun p1 ->
-        match Set.find_opt (equal_name p1) right with
+        match Set.find_opt (equal_name p1) packages_right with
         | Some p2 ->
           if OpamPackage.Version.equal p1.version p2.version
           then None
@@ -44,8 +52,8 @@ let compare left right =
                    version_right = p2.OpamPackage.version }
         | None ->
           None)
-      (Set.elements left)
-  and left = diff left right
-  and right = diff right left
+      (Set.elements packages_left)
+  and left = diff packages_left packages_right
+  and right = diff packages_right packages_left
   in
-  (same, version_diff, left, right)
+  (same, opam_diff, version_diff, left, right)