diff --git a/lib/plug/conn.ex b/lib/plug/conn.ex
index c4650355..319563f5 100644
--- a/lib/plug/conn.ex
+++ b/lib/plug/conn.ex
@@ -1677,7 +1677,8 @@ defmodule Plug.Conn do
     update_cookies(%{conn | resp_cookies: resp_cookies}, &Map.put(&1, key, value))
   end
 
-  defp maybe_sign_or_encrypt_cookie(conn, key, value, opts) do
+  @doc false
+  def maybe_sign_or_encrypt_cookie(%Conn{} = conn, key, value, opts) do
     {sign?, opts} = Keyword.pop(opts, :sign, false)
     {encrypt?, opts} = Keyword.pop(opts, :encrypt, false)
 
diff --git a/lib/plug/test.ex b/lib/plug/test.ex
index 76778511..5f3c720b 100644
--- a/lib/plug/test.ex
+++ b/lib/plug/test.ex
@@ -228,11 +228,23 @@ defmodule Plug.Test do
 
   @doc """
   Puts a request cookie.
+
+  ## Options
+
+    * `:max_age` - the cookie max-age, in seconds. Unset by default.
+    * `:sign` - when true, signs the cookie.
+    * `:encrypt` - when true, encrypts the cookie.
+
   """
-  @spec put_req_cookie(Conn.t(), binary, binary) :: Conn.t()
-  def put_req_cookie(conn, key, value) when is_binary(key) and is_binary(value) do
+  @spec put_req_cookie(Conn.t(), binary, any, keyword) :: Conn.t()
+  def put_req_cookie(%Conn{} = conn, key, value, opts \\ [])
+      when is_binary(key) and is_list(opts) do
     conn = delete_req_cookie(conn, key)
-    %{conn | req_headers: [{"cookie", "#{key}=#{value}"} | conn.req_headers]}
+    opts = Keyword.take(opts, [:max_age, :sign, :encrypt])
+
+    {to_send_value, _opts} = Conn.maybe_sign_or_encrypt_cookie(conn, key, value, opts)
+
+    %{conn | req_headers: [{"cookie", "#{key}=#{to_send_value}"} | conn.req_headers]}
   end
 
   @doc """
diff --git a/test/plug/conn_test.exs b/test/plug/conn_test.exs
index 65925125..4dfae684 100644
--- a/test/plug/conn_test.exs
+++ b/test/plug/conn_test.exs
@@ -1249,6 +1249,32 @@ defmodule Plug.ConnTest do
       assert get_cookies(new_conn)["foo"] == get_resp_cookies(conn)["foo"][:value]
       refute Map.has_key?(fetch_cookies(new_conn, encrypted: "foo").cookies, "foo")
     end
+
+    test "put_req_cookie/4 with sign: true" do
+      conn = secret_conn()
+      assert get_req_header(conn, "cookie") == []
+
+      conn = put_req_cookie(conn, "foo", "signed-bar", sign: true)
+      assert [cookie] = get_req_header(conn, "cookie")
+      assert cookie != "foo=signed-bar"
+      assert cookie =~ ~r"foo=[\w\_\.]+"
+
+      # indicates no options were set to the header, only the signed value
+      refute cookie =~ ~r/;/
+    end
+
+    test "put_req_cookie/4 with encrypt: true" do
+      conn = secret_conn()
+      assert get_req_header(conn, "cookie") == []
+
+      conn = put_req_cookie(conn, "foo", "encrypted-bar", encrypt: true)
+      assert [cookie] = get_req_header(conn, "cookie")
+      assert cookie != "foo=encrypted-bar"
+      assert cookie =~ ~r"foo=[\w\_\.]+"
+
+      # indicates no options were set to the header, only the encrypted value
+      refute cookie =~ ~r/;/
+    end
   end
 
   test "fetch_session/2 returns the same conn on subsequent calls" do