diff --git a/src/csrc/scalar_ops.cpp b/src/csrc/scalar_ops.cpp
index 8e81910..1e62c40 100644
--- a/src/csrc/scalar_ops.cpp
+++ b/src/csrc/scalar_ops.cpp
@@ -144,7 +144,7 @@ quad_richcompare(QuadPrecisionObject *self, PyObject *other, int cmp_op)
             return NULL;
         }
     }
-    else if (PyLong_CheckExact(other) || PyFloat_CheckExact(other)) {
+    else if (PyLong_Check(other) || PyFloat_Check(other)) {
         other_quad = QuadPrecision_from_object(other, backend);
         if (other_quad == NULL) {
             return NULL;
diff --git a/tests/test_quaddtype.py b/tests/test_quaddtype.py
index 58a8b7d..2a244ea 100644
--- a/tests/test_quaddtype.py
+++ b/tests/test_quaddtype.py
@@ -1350,6 +1350,33 @@ def test_comparisons(op, a, b):
     assert op_func(quad_a, quad_b) == op_func(float_a, float_b)
 
 
+@pytest.mark.parametrize("op", ["eq", "ne", "le", "lt", "ge", "gt"])
+@pytest.mark.parametrize(
+    "quad_val, other",
+    [
+        # bool is a subclass of int — exercises PyLong_Check (regression: gh-100)
+        (1, True),
+        (0, False),
+        (1, False),
+        (0, True),
+        (2, True),
+        # np.float64 is a subclass of float — exercises PyFloat_Check
+        (1, np.float64(1.0)),
+        (1, np.float64(2.0)),
+        (0, np.float64(-0.0)),
+    ],
+)
+def test_comparisons_with_python_subclasses(op, quad_val, other):
+    op_func = getattr(operator, op)
+    quad_a = QuadPrecision(quad_val)
+    expected = op_func(float(quad_val), float(other))
+
+    # Forward: QuadPrecision OP subclass-instance
+    assert op_func(quad_a, other) == expected, f"Failed {op} between QuadPrecision({quad_val}) and {other} (type {type(other)})"
+    # Reverse: subclass-instance OP QuadPrecision
+    assert op_func(other, quad_a) == op_func(float(other), float(quad_val)), f"Failed {op} between {other} (type {type(other)}) and QuadPrecision({quad_val})"
+
+
 @pytest.mark.parametrize("op", ["eq", "ne", "le", "lt", "ge", "gt"])
 @pytest.mark.parametrize("a", ["3.0", "12.5", "100.0", "0.0", "-0.0", "inf", "-inf", "nan", "-nan"])
 @pytest.mark.parametrize("b", ["3.0", "12.5", "100.0", "0.0", "-0.0", "inf", "-inf", "nan", "-nan"])