diff --git a/lib/pleroma/web/oauth/fallback_controller.ex b/lib/pleroma/web/oauth/fallback_controller.ex
index 1eeda3d24..f0fe3b578 100644
--- a/lib/pleroma/web/oauth/fallback_controller.ex
+++ b/lib/pleroma/web/oauth/fallback_controller.ex
@@ -9,7 +9,8 @@ defmodule Pleroma.Web.OAuth.FallbackController do
   # No user/password
   def call(conn, _) do
     conn
+    |> put_status(:unauthorized)
     |> put_flash(:error, "Invalid Username/Password")
-    |> OAuthController.authorize(conn.params)
+    |> OAuthController.authorize(conn.params["authorization"])
   end
 end
diff --git a/test/web/oauth/oauth_controller_test.exs b/test/web/oauth/oauth_controller_test.exs
index ccd552258..e0d3cb55f 100644
--- a/test/web/oauth/oauth_controller_test.exs
+++ b/test/web/oauth/oauth_controller_test.exs
@@ -34,6 +34,31 @@ test "redirects with oauth authorization" do
     assert Repo.get_by(Authorization, token: code)
   end
 
+  test "correctly handles wrong credentials", %{conn: conn} do
+    user = insert(:user)
+    app = insert(:oauth_app)
+
+    result =
+      conn
+      |> post("/oauth/authorize", %{
+        "authorization" => %{
+          "name" => user.nickname,
+          "password" => "wrong",
+          "client_id" => app.client_id,
+          "redirect_uri" => app.redirect_uris,
+          "state" => "statepassed"
+        }
+      })
+      |> html_response(:unauthorized)
+
+    # Keep the details
+    assert result =~ app.client_id
+    assert result =~ app.redirect_uris
+
+    # Error message
+    assert result =~ "Invalid"
+  end
+
   test "issues a token for an all-body request" do
     user = insert(:user)
     app = insert(:oauth_app)