diff --git a/source/domains/abstractProductDomain.ml b/source/domains/abstractProductDomain.ml
index 60760bc1c95..b7bffd985e4 100644
--- a/source/domains/abstractProductDomain.ml
+++ b/source/domains/abstractProductDomain.ml
@@ -29,11 +29,8 @@ module Make (Config : PRODUCT_CONFIG) = struct
 
   type product = element array
 
-  module IntMap = Map.Make (struct
-    type t = int
-
-    let compare = compare
-  end)
+  module IntMap = Map.Make (Int)
+  module IntSet = Set.Make (Int)
 
   type abstract_slot = Slot : 'a Config.slot -> abstract_slot [@@unbox]
 
@@ -56,8 +53,17 @@ module Make (Config : PRODUCT_CONFIG) = struct
   (* The route map indicates for each part under a product element which slot the element is in *)
   let route_map : int IntMap.t =
     let map = ref IntMap.empty in
+    let duplicates = ref IntSet.empty in
     let gather (route : int) (type a) (part : a part) =
-      map := IntMap.add (part_id part) route !map
+      let part_id = part_id part in
+      (* Ignore parts that are present in multiple slots. *)
+      if not (IntSet.mem part_id !duplicates) then
+        if not (IntMap.mem part_id !map) then
+          map := IntMap.add part_id route !map
+        else begin
+          map := IntMap.remove part_id !map;
+          duplicates := IntSet.add part_id !duplicates
+        end
     in
     Array.iteri
       (fun route (Slot slot) ->
diff --git a/source/domains/test/abstractDomainTest.ml b/source/domains/test/abstractDomainTest.ml
index fb755879348..65691d13a2f 100644
--- a/source/domains/test/abstractDomainTest.ml
+++ b/source/domains/test/abstractDomainTest.ml
@@ -2684,6 +2684,61 @@ end
 
 module TestFlatString = TestAbstractDomain (FlatString)
 
+module TestProductAmbiguousPart = struct
+  module StringSet = AbstractSetDomain.Make (String)
+
+  module Slots = struct
+    type 'a slot =
+      | Left : StringSet.t slot
+      | Right : StringSet.t slot
+
+    let slots = 2
+
+    let slot_name (type a) (slot : a slot) =
+      match slot with
+      | Left -> "left"
+      | Right -> "right"
+
+
+    let slot_domain (type a) (slot : a slot) =
+      match slot with
+      | Left -> (module StringSet : AbstractDomain.S with type t = a)
+      | Right -> (module StringSet : AbstractDomain.S with type t = a)
+
+
+    let strict (type a) (_slot : a slot) = false
+  end
+
+  include AbstractProductDomain.Make (Slots)
+
+  let suite () =
+    let assert_raises_any f =
+      try
+        let _ = f () in
+        assert_failure "Expected an exception to be raised"
+      with
+      | _ -> ()
+    in
+    let test_create _ =
+      assert_raises_any (fun () -> create [Part (StringSet.Self, StringSet.bottom)])
+    in
+    let test_transform _ =
+      assert_raises_any (fun () -> transform StringSet.Self Map ~f:(StringSet.add "x") bottom)
+    in
+    let test_update_get _ =
+      let x = StringSet.singleton "x" in
+      assert_equal (bottom |> update Slots.Left x |> get Slots.Left) x;
+      assert_equal (bottom |> update Slots.Right x |> get Slots.Right) x;
+      assert_equal (bottom |> update Slots.Left x |> get Slots.Right) StringSet.bottom;
+      assert_equal (bottom |> update Slots.Right x |> get Slots.Left) StringSet.bottom
+    in
+    [
+      "test_create" >:: test_create;
+      "test_transform" >:: test_transform;
+      "test_update_get" >:: test_update_get;
+    ]
+end
+
 let () =
   "abstractDomainTest"
   >::: [
@@ -2701,5 +2756,6 @@ let () =
          "tree" >::: TestTreeDomain.suite ();
          "string_biset" >::: TestOverUnderStringSet.suite ();
          "flat_string" >::: TestFlatString.suite ();
+         "product_ambiguous_part" >::: TestProductAmbiguousPart.suite ();
        ]
   |> run_test_tt_main