diff --git a/.coveragerc b/.coveragerc
index 3572e84b192e9b8071ba09f33e86ea4c61af093e..8914c41097ddd01ed3f31924a273266e0c4a46a0 100644
--- a/.coveragerc
+++ b/.coveragerc
@@ -1,3 +1,12 @@
 [run]
 plugins = Cython.Coverage
-omit = */tests/*
+omit =
+     */tests/*
+     kwant/graph/dissection.py
+     kwant/_kwant_version.py
+     */__init__.py
+branch = True
+[report]
+exclude_lines =
+    skip coverage
+    @abc.abstractmethod
diff --git a/kwant/digest.py b/kwant/digest.py
index cd53095efa209deb5e55926a809ae6715f2b1b3e..0181032ffdedf719f901ce4692828b5f21ea00bf 100644
--- a/kwant/digest.py
+++ b/kwant/digest.py
@@ -72,7 +72,7 @@ def gauss(input, salt=''):
     return cos(a * TWOPI) * sqrt(-2.0 * log(1.0 - b))
 
 
-def test(n=20000):
+def test(n=20000):  # skip coverage
     """Test the generator with the dieharder suite generating n**2 samples.
 
     Executing this function may take a very long time.