diff --git a/lib/flop/adapter/ecto.ex b/lib/flop/adapter/ecto.ex
index f5fec9bf..3fb78706 100644
--- a/lib/flop/adapter/ecto.ex
+++ b/lib/flop/adapter/ecto.ex
@@ -256,6 +256,11 @@ defmodule Flop.Adapter.Ecto do
 
   @impl Flop.Adapter
   def apply_order_by(query, directions, opts) do
+    if Ecto.Queryable.to_query(query).order_bys != [] do
+      Logger.warning("The query you passed to flop includes order_by.\
+        This may interfere with Flop's ordering and pagination features.")
+    end
+
     case opts[:for] do
       nil ->
         Query.order_by(query, ^directions)
diff --git a/test/adapters/ecto/cases/flop_test.exs b/test/adapters/ecto/cases/flop_test.exs
index 5a4be393..164cfda9 100644
--- a/test/adapters/ecto/cases/flop_test.exs
+++ b/test/adapters/ecto/cases/flop_test.exs
@@ -6,6 +6,7 @@ defmodule Flop.Adapters.Ecto.FlopTest do
 
   doctest Flop, import: true
 
+  import ExUnit.CaptureLog
   import Ecto.Query
   import Flop.Factory
   import Flop.Generators
@@ -167,6 +168,15 @@ defmodule Flop.Adapters.Ecto.FlopTest do
                for: Owner
              ) == Enum.reverse(expected)
     end
+
+    test "warns if query passed to Flop already included ordering" do
+      query = from p in Pet, order_by: :species
+
+      assert capture_log(fn ->
+               Flop.all(query, %Flop{order_by: [:species, :name]})
+             end) =~
+               "This may interfere with Flop's ordering and pagination features"
+    end
   end
 
   describe "filtering" do