diff --git a/CHANGELOG.md b/CHANGELOG.md
index 3d6b8161ef8..66cf8ec3336 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -118,6 +118,7 @@ This release is compatible with NumPy 2.5.
 * Fixed incorrect results of `dpnp.tensor.vecdot` in some cases with strided outputs and of `dpnp.tensor` reductions, `dpnp.tensor.vecdot` and `dpnp.tensor.matmul` on large inputs with some data types [#3082](https://github.com/IntelPython/dpnp/pull/3082)
 * Fixed `dpnp.median` and `dpnp.nanmedian` raising a `ValueError` for a tuple `axis` when a kept dimension has size 0 [#3081](https://github.com/IntelPython/dpnp/pull/3081)
 * Fixed a `RuntimeError` raised by `dpnp.tensor` kernels launched over more than `INT_MAX` work-items when built with DPC++ compiler 2026.2 or newer, by also passing `-fno-sycl-id-queries-fit-in-int` to the linker [#3089](https://github.com/IntelPython/dpnp/pull/3089)
+* Fixed the CuPy-based `dpnp.scipy` tests under `dpnp/tests/third_party/cupyx/scipy_tests/` missing from the `dpnp` package, so they never ran against an installed package [#3102](https://github.com/IntelPython/dpnp/pull/3102)
 
 ### Security
 
diff --git a/dpnp/tests/third_party/cupyx/scipy_tests/sparse_tests/test_linalg.py b/dpnp/tests/third_party/cupyx/scipy_tests/sparse_tests/test_linalg.py
index c77096a289c..8e5f6001da6 100644
--- a/dpnp/tests/third_party/cupyx/scipy_tests/sparse_tests/test_linalg.py
+++ b/dpnp/tests/third_party/cupyx/scipy_tests/sparse_tests/test_linalg.py
@@ -625,7 +625,10 @@ def _make_matrix(self):
         a[mask > self.density] = 0
         m = None
         if self.M == "jacobi":
-            m = numpy.diag(1.0 / numpy.diag(a))
+            # NOTE: at this density diag(a) is mostly zero, so upstream's
+            # 1/diag(a) is inf and both sides return NaN; use 1 there.
+            d = numpy.diag(a)
+            m = numpy.diag(1.0 / numpy.where(d == 0, 1, d))
         return a, m
 
     def _make_normalized_vector(self):
diff --git a/setup.py b/setup.py
index 08fadda683d..23145fab005 100644
--- a/setup.py
+++ b/setup.py
@@ -64,10 +64,12 @@
             "tests/tensor/*.py",
             "tests/tensor/*/*.py",
             "tests/testing/*.py",
+            "tests/third_party/*.py",
             "tests/third_party/cupy/*.py",
             "tests/third_party/cupy/*/*.py",
             "tests/third_party/cupyx/*.py",
             "tests/third_party/cupyx/*/*.py",
+            "tests/third_party/cupyx/*/*/*.py",
         ],
     },
     include_package_data=False,