diff --git a/test/test_grudge.py b/test/test_grudge.py
index 096882aa79c3760375b17f6628c9605843145eef..7778105eb8e2e2b3525a4d03bb61ad24f5a5f84a 100644
--- a/test/test_grudge.py
+++ b/test/test_grudge.py
@@ -322,8 +322,9 @@ def test_surface_mass_operator_inverse(ctx_factory, name):
 
     logger.info("inverse mass error\n%s", str(eoc))
 
-    assert eoc.max_error() < 5.0e-09 \
-            or eoc.order_estimate() > builder.order
+    # NOTE: both cases give 1.0e-16-ish at the moment, but just to be on the
+    # safe side, choose a slightly larger tolerance
+    assert eoc.max_error() < 1.0e-14
 
 # }}}