diff --git a/pyvdrm/asi2.py b/pyvdrm/asi2.py
index 06f0ab0..4e0ea5c 100644
--- a/pyvdrm/asi2.py
+++ b/pyvdrm/asi2.py
@@ -220,7 +220,7 @@ def __repr__(self):
 
     def __call__(self, env):
         for mutation_set in env:
-            intersection = mutation_set.mutations & self.mutations.mutations
+            intersection = self.mutations.mutations & mutation_set.mutations
             if len(intersection) > 0:
                 return Score(True, intersection)
         return None
diff --git a/pyvdrm/tests/test_asi2.py b/pyvdrm/tests/test_asi2.py
index b567c13..7577211 100644
--- a/pyvdrm/tests/test_asi2.py
+++ b/pyvdrm/tests/test_asi2.py
@@ -47,11 +47,18 @@ def test_asi2_compat(self):
 
 # noinspection SqlNoDataSourceInspection,SqlDialectInspection
 class TestRuleSemantics(unittest.TestCase):
-    
     def test_score_from(self):
         rule = ASI2("SCORE FROM ( 100G => 10, 101D => 20 )")
         self.assertEqual(rule(VariantCalls("100G 102G")), 10)
 
+    def test_score_residues(self):
+        rule = ASI2("SCORE FROM ( 100G => 10, 101D => 20 )")
+        expected_residue = repr({Mutation('S100G')})
+
+        result = rule.dtree(VariantCalls("S100G R102G"))
+
+        self.assertEqual(expected_residue, repr(result.residues))
+
     def test_score_from_max(self):
         rule = ASI2("SCORE FROM (MAX (100G => 10, 101D => 20, 102D => 30))")
         self.assertEqual(rule(VariantCalls("100G 101D")), 20)