diff --git a/com/atomic_test.go b/com/atomic_test.go
index 2c5e53f..c3509b2 100644
--- a/com/atomic_test.go
+++ b/com/atomic_test.go
@@ -70,3 +70,46 @@ func TestAtomic_Swap(t *testing.T) {
 		})
 	}
 }
+
+func TestAtomic_CompareAndSwap(t *testing.T) {
+	subtests := []struct {
+		name    string
+		init    bool
+		io      testInterface
+		old     testInterface
+		new     testInterface
+		swapped bool
+	}{
+		{"uninitialized_nil_nonzero", false, nil, nil, &testImpl{}, false},
+		{"uninitialized_nilptr_nonzero", false, nil, (*testImpl)(nil), &testImpl{}, false},
+		{"uninitialized_nonzero_nilptr", false, nil, &testImpl{}, (*testImpl)(nil), false},
+		{"nil_nil_nonzero", true, nil, nil, &testImpl{}, true},
+		{"nil_nilptr_nonzero", true, nil, (*testImpl)(nil), &testImpl{}, false},
+		{"nil_nonzero_nilptr", true, nil, &testImpl{}, (*testImpl)(nil), false},
+		{"nilptr_nil_nonzero", true, (*testImpl)(nil), nil, &testImpl{}, false},
+		{"nilptr_nilptr_nonzero", true, (*testImpl)(nil), (*testImpl)(nil), &testImpl{}, true},
+		{"nilptr_nonzero_nil", true, (*testImpl)(nil), &testImpl{}, nil, false},
+		{"nonzero_nil_nilptr", true, &testImpl{}, nil, (*testImpl)(nil), false},
+		{"nonzero_nilptr_nil", true, &testImpl{}, (*testImpl)(nil), nil, false},
+		{"nonzero_nonzero_nilptr", true, &testImpl{}, &testImpl{}, (*testImpl)(nil), false},
+	}
+
+	for _, st := range subtests {
+		t.Run(st.name, func(t *testing.T) {
+			var a Atomic[testInterface]
+			if st.init {
+				a.Store(st.io)
+			}
+
+			require.Equal(t, st.swapped, a.CompareAndSwap(st.old, st.new), "CompareAndSwap return value")
+
+			if v, ok := a.Load(); st.swapped {
+				require.True(t, ok, "Load second return value")
+				require.Equal(t, st.new, v, "Load first return value")
+			} else {
+				require.Equal(t, st.init, ok, "Load second return value")
+				require.Equal(t, st.io, v, "Load first return value")
+			}
+		})
+	}
+}