diff --git a/apps/transport/lib/validators/netex_validator.ex b/apps/transport/lib/validators/netex_validator.ex
index e7ec9bea58..7fceddbd98 100644
--- a/apps/transport/lib/validators/netex_validator.ex
+++ b/apps/transport/lib/validators/netex_validator.ex
@@ -36,7 +36,7 @@ defmodule Transport.Validators.NeTEx do
           resource_history.id,
           result_url,
           %{elapsed_seconds: elapsed_seconds, retries: retries},
-          errors
+          demote_non_xsd_errors(errors)
         )
 
         :ok
@@ -76,7 +76,7 @@ defmodule Transport.Validators.NeTEx do
           # result_url in metadata?
           {:ok,
            %{
-             "validations" => index_messages(errors),
+             "validations" => errors |> demote_non_xsd_errors() |> index_messages(),
              "metadata" => %{elapsed_seconds: elapsed_seconds, retries: retries}
            }}
 
@@ -344,4 +344,20 @@ defmodule Transport.Validators.NeTEx do
   defp client do
     Transport.EnRouteChouetteValidClient.Wrapper.impl()
   end
+
+  defp demote_non_xsd_errors(errors), do: Enum.map(errors, &demote_non_xsd_error(&1))
+
+  defp demote_non_xsd_error(%{"criticity" => criticity, "code" => code} = error) do
+    criticity =
+      if String.starts_with?(code, "xsd-") do
+        criticity
+      else
+        case criticity do
+          "error" -> "warning"
+          _ -> criticity
+        end
+      end
+
+    Map.update!(error, "criticity", fn _ -> criticity end)
+  end
 end
diff --git a/apps/transport/test/transport/validators/netex_validator_test.exs b/apps/transport/test/transport/validators/netex_validator_test.exs
index cd41dda0e0..20312562b5 100644
--- a/apps/transport/test/transport/validators/netex_validator_test.exs
+++ b/apps/transport/test/transport/validators/netex_validator_test.exs
@@ -15,6 +15,12 @@ defmodule Transport.Validators.NeTExTest do
   setup :verify_on_exit!
 
   @sample_error_messages [
+    %{
+      "code" => "xsd-1871",
+      "criticity" => "error",
+      "message" =>
+        "Element '{http://www.netex.org.uk/netex}OppositeDIrectionRef': This element is not expected. Expected is ( {http://www.netex.org.uk/netex}OppositeDirectionRef )."
+    },
     %{
       "code" => "uic-operating-period",
       "message" => "Resource 23504000009 hasn't expected class but Netex::OperatingPeriod",
@@ -70,18 +76,26 @@ defmodule Transport.Validators.NeTExTest do
       assert multi_validation.metadata.metadata == %{"retries" => 0, "elapsed_seconds" => 31}
 
       assert multi_validation.result == %{
+               "xsd-1871" => [
+                 %{
+                   "code" => "xsd-1871",
+                   "criticity" => "error",
+                   "message" =>
+                     "Element '{http://www.netex.org.uk/netex}OppositeDIrectionRef': This element is not expected. Expected is ( {http://www.netex.org.uk/netex}OppositeDirectionRef )."
+                 }
+               ],
                "uic-operating-period" => [
                  %{
                    "code" => "uic-operating-period",
                    "message" => "Resource 23504000009 hasn't expected class but Netex::OperatingPeriod",
-                   "criticity" => "error"
+                   "criticity" => "warning"
                  }
                ],
                "valid-day-bits" => [
                  %{
                    "code" => "valid-day-bits",
                    "message" => "Mandatory attribute valid_day_bits not found",
-                   "criticity" => "error"
+                   "criticity" => "warning"
                  }
                ],
                "frame-arret-resources" => [
@@ -121,18 +135,26 @@ defmodule Transport.Validators.NeTExTest do
       expect_get_messages(validation_id, @sample_error_messages)
 
       validation_result = %{
+        "xsd-1871" => [
+          %{
+            "code" => "xsd-1871",
+            "criticity" => "error",
+            "message" =>
+              "Element '{http://www.netex.org.uk/netex}OppositeDIrectionRef': This element is not expected. Expected is ( {http://www.netex.org.uk/netex}OppositeDirectionRef )."
+          }
+        ],
         "uic-operating-period" => [
           %{
             "code" => "uic-operating-period",
             "message" => "Resource 23504000009 hasn't expected class but Netex::OperatingPeriod",
-            "criticity" => "error"
+            "criticity" => "warning"
           }
         ],
         "valid-day-bits" => [
           %{
             "code" => "valid-day-bits",
             "message" => "Mandatory attribute valid_day_bits not found",
-            "criticity" => "error"
+            "criticity" => "warning"
           }
         ],
         "frame-arret-resources" => [
@@ -160,11 +182,12 @@ defmodule Transport.Validators.NeTExTest do
       expect_get_messages(validation_id, @sample_error_message)
 
       validation_result = %{
-        "uic-operating-period" => [
+        "xsd-1871" => [
           %{
-            "code" => "uic-operating-period",
-            "message" => "Resource 23504000009 hasn't expected class but Netex::OperatingPeriod",
-            "criticity" => "error"
+            "code" => "xsd-1871",
+            "criticity" => "error",
+            "message" =>
+              "Element '{http://www.netex.org.uk/netex}OppositeDIrectionRef': This element is not expected. Expected is ( {http://www.netex.org.uk/netex}OppositeDirectionRef )."
           }
         ]
       }