diff --git a/lib/adapters/datadog.ex b/lib/adapters/datadog.ex
index 8cecce0..ed78865 100644
--- a/lib/adapters/datadog.ex
+++ b/lib/adapters/datadog.ex
@@ -248,7 +248,7 @@ defmodule Spandex.Adapters.Datadog do
   """
   @impl Spandex.Adapters.Adapter
   @spec continue_trace(String.t(), term, term, Keyword.t()) :: {:ok, term} | {:error, term}
-  def continue_trace(name, trace_id, span_id, opts) do
+  def continue_trace(name, trace_id, span_id, opts) when is_integer(trace_id) and is_integer(span_id) do
     trace = get_trace(:undefined)
 
     cond do
@@ -306,8 +306,18 @@ defmodule Spandex.Adapters.Datadog do
     conn
     |> Plug.Conn.get_req_header(header_name)
     |> List.first()
+    |> parse_header()
   end
 
+  defp parse_header(header) when is_bitstring(header) do
+    case Integer.parse(header) do
+      {int, _} -> int
+      _        -> nil
+    end
+  end
+
+  defp parse_header(_header), do: nil
+
   @spec get_trace(term) :: term
   defp get_trace(default \\ nil) do
     Process.get(:spandex_trace, default)
diff --git a/test/plug/start_trace_test.exs b/test/plug/start_trace_test.exs
index 2b3f9c7..2c4bf39 100644
--- a/test/plug/start_trace_test.exs
+++ b/test/plug/start_trace_test.exs
@@ -99,9 +99,9 @@ defmodule Spandex.Plug.StartTraceTest do
 
       new_conn = StartTrace.call(conn, ignored_routes: [], ignored_methods: [], tracer: Tracer)
 
-      assert %{trace_id: "12345", parent_id: "67890"} = Tracer.current_span()
+      assert %{trace_id: 12345, parent_id: 67890} = Tracer.current_span()
 
-      refute Tracer.current_span_id() == "67890"
+      refute Tracer.current_span_id() == 67890
       refute is_nil(Tracer.current_span_id())
 
       assert new_conn.assigns[:spandex_trace_request?]