--- test/test_download.rb	2018-01-22 02:26:56.440016436 +0100
+++ test/test_download.rb	2018-01-22 02:32:46.076017270 +0100
@@ -116,7 +116,9 @@
 
   def test_download_io_with_recursive_should_raise_error
     expect_scp_session "-f -r /path/to/remote.txt"
-    assert_raises(Net::SCP::Error) { scp.download!("/path/to/remote.txt", StringIO.new, :recursive => true) }
+    Net::SSH::Test::Extensions::IO.with_test_extension do
+      assert_raises(Net::SCP::Error) { scp.download!("/path/to/remote.txt", StringIO.new, :recursive => true) }
+    end
   end
 
   def test_download_io_with_preserve_should_ignore_preserve
@@ -154,8 +156,9 @@
       channel.sends_ok
       channel.gets_data "D0755 0 remote\n"
     end
-
-    assert_raises(Net::SCP::Error) { scp.download!("/path/to/remote") }
+    Net::SSH::Test::Extensions::IO.with_test_extension do
+      assert_raises(Net::SCP::Error) { scp.download!("/path/to/remote") }
+    end
   end
 
   def test_download_should_raise_error_if_gets_not_ok