@@ -410,9 +410,12 @@ npy_update_operand_for_scalar(
          * in all other cases, we don't technically consider equivalent.
          * NOTE(seberg): I don't think we should be beholden to this logic.
          */
+        const char *name = (scalar != NULL) ? Py_TYPE(scalar)->tp_name :
+                ((PyArray_FLAGS(*operand) & NPY_ARRAY_WAS_PYTHON_INT) ? "int" :
+                 ((PyArray_FLAGS(*operand) & NPY_ARRAY_WAS_PYTHON_FLOAT) ? "float" : "complex"));
         PyErr_Format(PyExc_TypeError,
             "cannot cast Python %s to %S under the casting rule 'equiv'",
-            Py_TYPE(scalar)->tp_name, descr);
+            name, descr);
         return -1;
     }
 
 
@@ -3256,6 +3256,13 @@ def test_resolve_dtypes_basic(self):
         r = np.add.resolve_dtypes((f4, int, None))
         assert r == (f4, f4, f4)
 
+        msg = r"cannot cast Python.*under the casting rule 'equiv'"
+        for pytype, dtype in [(int, "uint8"), (float, "float32"),
+                              (complex, "complex64")]:
+            with pytest.raises(TypeError, match=msg):
+                np.add.resolve_dtypes((np.dtype(dtype), pytype, None),
+                                      casting="equiv")
+
         with pytest.raises(TypeError):
             np.add.resolve_dtypes((i4, f4, None), casting="no")