diff --git a/tests/test_dagset.py b/tests/test_dagset.py
index aeadb5b..785875d 100644
--- a/tests/test_dagset.py
+++ b/tests/test_dagset.py
@@ -137,7 +137,6 @@ class TestDAGSetCallbacks:
             assert 3 in removed
 
 
-
 class TestDAGSetInPlaceOperators:
     """Test in-place set operators."""
 
@@ -157,6 +156,12 @@ class TestDAGSetInPlaceOperators:
             s |= "xyz"
             assert "xyz" in s
 
+        def test_dagset(self) -> None:
+            s = DAGSetView({1, 2})
+            other = DAGSetView({3, 4})
+            s |= other
+            assert set(s) == {1, 2, 3, 4}
+
     class TestIAdd:
         def test_set(self) -> None:
             s = DAGSetView({1, 2})
@@ -173,6 +178,12 @@ class TestDAGSetInPlaceOperators:
             s += "b"
             assert "b" in s
 
+        def test_dagset(self) -> None:
+            s = DAGSetView({1, 2})
+            other = DAGSetView({3, 4})
+            s += other
+            assert set(s) == {1, 2, 3, 4}
+
     class TestISub:
         def test_set(self) -> None:
             s = DAGSetView({1, 2, 3, 4})
@@ -189,6 +200,12 @@ class TestDAGSetInPlaceOperators:
             s -= "b"
             assert set(s) == {"a", "c"}
 
+        def test_dagset(self) -> None:
+            s = DAGSetView({1, 2, 3, 4})
+            other = DAGSetView({2, 3})
+            s -= other
+            assert set(s) == {1, 4}
+
     class TestIAnd:
         def test_set(self) -> None:
             s = DAGSetView({1, 2, 3})
@@ -200,6 +217,12 @@ class TestDAGSetInPlaceOperators:
             s &= [2, 3]
             assert set(s) == {2, 3}
 
+        def test_dagset(self) -> None:
+            s = DAGSetView({1, 2, 3})
+            other = DAGSetView({2, 3, 4})
+            s &= other
+            assert set(s) == {2, 3}
+
     class TestIXor:
         def test_set(self) -> None:
             s = DAGSetView({1, 2, 3})
@@ -210,3 +233,9 @@ class TestDAGSetInPlaceOperators:
             s = DAGSetView({1, 2})
             s ^= [2, 3]
             assert set(s) == {1, 3}
+
+        def test_dagset(self) -> None:
+            s = DAGSetView({1, 2, 3})
+            other = DAGSetView({3, 4, 5})
+            s ^= other
+            assert set(s) == {1, 2, 4, 5}