diff --git a/tests/test_utils.py b/tests/test_utils.py
index 92367ea..d1bdf0d 100644
--- a/tests/test_utils.py
+++ b/tests/test_utils.py
@@ -1,10 +1,9 @@
-from copy import copy
-from types import MethodType
-
 import aesara.tensor as at
 import numpy as np
 import pytest
+from aesara.graph.basic import Apply
 from aesara.tensor.exceptions import ShapeError
+from aesara.tensor.random.basic import NormalRV
 
 from aehmc.utils import RaveledParamsMap
 
@@ -81,12 +80,25 @@ def test_RaveledParamsMap_dtype():
 
 
 def test_RaveledParamsMap_bad_infer_shape():
-    bad_normal_op = copy(at.random.normal)
-
-    def bad_infer_shape(self, *args, **kwargs):
-        raise ShapeError()
-
-    bad_normal_op.infer_shape = MethodType(bad_infer_shape, bad_normal_op)
+    class BadNormalRV(NormalRV):
+        def make_node(self, *args, **kwargs):
+            res = super().make_node(*args, **kwargs)
+            # Drop static `Type`-level shape information
+            rv_out = res.outputs[1]
+            outputs = [
+                res.outputs[0].clone(),
+                at.tensor(dtype=rv_out.type.dtype, shape=(None,) * rv_out.type.ndim),
+            ]
+            return Apply(
+                self,
+                res.inputs,
+                outputs,
+            )
+
+        def infer_shape(self, *args, **kwargs):
+            raise ShapeError()
+
+    bad_normal_op = BadNormalRV()
 
     size = (3, 2)
     beta_rv = bad_normal_op(0, 1, size=size, name="beta")