Unit test the test harness
diff --git a/tests/primitives/test_utils.py b/tests/primitives/test_utils.py
new file mode 100644
index 0000000..4666ece
--- /dev/null
+++ b/tests/primitives/test_utils.py
@@ -0,0 +1,14 @@
+import pytest
+
+from .utils import encrypt_test
+
+
+class TestEncryptTest(object):
+    def test_skips_if_only_if_returns_false(self):
+        with pytest.raises(pytest.skip.Exception) as exc_info:
+            encrypt_test(
+                None, None, None, None,
+                only_if=lambda api: False,
+                skip_message="message!"
+            )
+        assert exc_info.value.args[0] == "message!"