diff --git a/test/unit/plugins/guests/linux/cap/port_test.rb b/test/unit/plugins/guests/linux/cap/port_test.rb
new file mode 100644
index 000000000..36792e8e2
--- /dev/null
+++ b/test/unit/plugins/guests/linux/cap/port_test.rb
@@ -0,0 +1,30 @@
+require_relative "../../../../base"
+
+describe "VagrantPlugins::GuestLinux::Cap::Port" do
+  let(:caps) do
+    VagrantPlugins::GuestLinux::Plugin
+      .components
+      .guest_capabilities[:linux]
+  end
+
+  let(:machine) { double("machine") }
+  let(:comm) { VagrantTests::DummyCommunicator::Communicator.new(machine) }
+
+  before do
+    allow(machine).to receive(:communicate).and_return(comm)
+  end
+
+  after do
+    comm.verify_expectations!
+  end
+
+  describe ".port_open_check" do
+    let(:cap) { caps.get(:port_open_check) }
+
+    it "checks if the port is open" do
+      port = 8080
+      comm.expect_command("nc -z -w2 127.0.0.1 #{port}")
+      cap.port_open_check(machine, port)
+    end
+  end
+end