diff --git a/.coveragerc b/.coveragerc
new file mode 100644
index 0000000..ff6415d
--- /dev/null
+++ b/.coveragerc
@@ -0,0 +1,7 @@
+[report]
+exclude_lines =
+    # Have to re-enable the standard pragma
+    pragma: no cover
+
+    # Don't complain if tests don't hit defensive assertion code:
+    raise NotImplementedError