diff --git a/t/05-instance.t b/t/05-instance.t
new file mode 100644
index 0000000..199a243
--- /dev/null
+++ b/t/05-instance.t
@@ -0,0 +1,31 @@
+#!perl -T
+use 5.006;
+use strict;
+use warnings FATAL => 'all';
+use Test::More;
+use WebService::GarminConnect;
+
+plan tests => 4;
+
+# Both the username and password are required arguments.
+my $gc;
+eval {
+  $gc = WebService::GarminConnect->new();
+};
+is($gc, undef, 'constructor fails with no arguments');
+
+eval {
+  $gc = WebService::GarminConnect->new(username => 'user1');
+};
+is($gc, undef, 'constructor fails with just username');
+
+eval {
+  $gc = WebService::GarminConnect->new(password => 'mypass');
+};
+is($gc, undef, 'constructor fails with just password');
+
+eval {
+  $gc = WebService::GarminConnect->new(username => 'user1',
+                                       password => 'mypass');
+};
+isnt($gc, undef, 'constructor succeeds with both username and password');