diff --git a/gnu/packages/python-science.scm b/gnu/packages/python-science.scm
index 47a837ffd9..c485a30633 100644
--- a/gnu/packages/python-science.scm
+++ b/gnu/packages/python-science.scm
@@ -6685,28 +6685,29 @@ Python style, together with a fast and comfortable execution environment.")
     (version "1.2.1")
     (source
      (origin
-       (method url-fetch)
-       (uri (pypi-uri "orsopy" version))
+       (method git-fetch)
+       (uri (git-reference
+             (url "https://github.com/reflectivity/orsopy")
+             (commit (string-append "v" version))))
+       (file-name (git-file-name name version))
        (sha256
-        (base32 "1fpp9h93p55sa4cfsix71ibj74fdrgh2kzmw2rg06ya8q0c4ndik"))))
-    (build-system python-build-system)
+        (base32 "15av7b38h9x0f09dzxb111r2kxm6an461l9ajb01r8r7mv7m5bw9"))))
+    (build-system pyproject-build-system)
     (arguments
      (list
-      #:phases
-      #~(modify-phases %standard-phases
-          (replace 'check
-            (lambda* (#:key tests? #:allow-other-keys)
-              (when tests?
-                (invoke "pytest" "-vv"
-                        ;; These tests require network access.
-                        "--ignore=orsopy/slddb/tests/test_webapi.py"
-                        "--deselect=orsopy/fileio/tests/test_model_language.py::TestSubStack::test_resolve_layers"
-                        "--deselect=orsopy/fileio/tests/test_model_language.py::TestMaterial::test_density_lookup_elements"
-                        "--deselect=orsopy/fileio/tests/test_model_language.py::TestSampleModel::test_resolve_to_layers")))))))
+      #:test-flags
+      ;; These tests require network access.
+      #~(list "--ignore=orsopy/slddb/tests/test_webapi.py"
+              (map (lambda (test)
+                     (string-append "--deselect=orsopy/fileio/tests/"
+                                    "test_model_language.py::" test))
+                   (list "TestSubStack::test_resolve_layers"
+                         "TestMaterial::test_density_lookup_elements"
+                         "TestSampleModel::test_resolve_to_layers")))))
     (propagated-inputs
      (list python-numpy python-pyyaml python-jsonschema python-h5py))
     (native-inputs
-     (list python-pytest python-pint))
+     (list python-pint python-pytest python-setuptools))
     (home-page "https://github.com/reflectivity/orsopy")
     (synopsis "Open Reflectometry Standards Organization Python tools")
     (description