diff --git a/patsy/polynomials.py b/patsy/polynomials.py
index 85a35d1..31b4541 100644
--- a/patsy/polynomials.py
+++ b/patsy/polynomials.py
@@ -145,6 +145,8 @@ def test_poly_compat():
     from patsy.test_poly_data import (R_poly_test_x,
                                       R_poly_test_data,
                                       R_poly_num_tests)
+    from numpy.testing import assert_allclose
+
     lines = R_poly_test_data.split("\n")
     tests_ran = 0
     start_idx = lines.index("--BEGIN TEST CASE--")
@@ -172,6 +174,14 @@ def test_poly_compat():
         output = np.asarray(eval(test_data["output"]))
         # Do the actual test
         check_stateful(Poly, False, R_poly_test_x, output, **kwargs)
+        raw_poly = Poly.vander(R_poly_test_x, kwargs['degree'])
+        if kwargs['raw']:
+            actual = raw_poly[:, 1:]
+        else:
+            alpha, norm, beta = Poly.gen_qr(raw_poly, kwargs['degree'])
+            actual = Poly.apply_qr(R_poly_test_x, kwargs['degree'], alpha,
+                                   norm, beta)[:, 1:]
+        assert_allclose(actual, output)
         tests_ran += 1
         # Set up for the next one
         start_idx = stop_idx + 1