diff --git a/pkgs/development/python-modules/dedupe-pylbfgs/default.nix b/pkgs/development/python-modules/dedupe-pylbfgs/default.nix
index a06645526753..738177ec8106 100644
--- a/pkgs/development/python-modules/dedupe-pylbfgs/default.nix
+++ b/pkgs/development/python-modules/dedupe-pylbfgs/default.nix
@@ -26,6 +26,10 @@ buildPythonPackage rec {
     hash = "sha256-H416dgZQxyqsnhmlK5keW8cJWY6gea4mebVuP0IEVOU=";
   };
 
+  patches = [
+    ./tests-numpy-2.4.patch # https://github.com/dedupeio/pylbfgs/pull/52
+  ];
+
   build-system = [
     cython
     numpy
diff --git a/pkgs/development/python-modules/dedupe-pylbfgs/tests-numpy-2.4.patch b/pkgs/development/python-modules/dedupe-pylbfgs/tests-numpy-2.4.patch
new file mode 100644
index 000000000000..d90dbc0a69e5
--- /dev/null
+++ b/pkgs/development/python-modules/dedupe-pylbfgs/tests-numpy-2.4.patch
@@ -0,0 +1,25 @@
+diff --git a/tests/test_lbfgs.py b/tests/test_lbfgs.py
+index 1af91ef..65e2da9 100644
+--- a/tests/test_lbfgs.py
++++ b/tests/test_lbfgs.py
+@@ -28,16 +28,16 @@ class TestOWLQN:
+ 
+     def test_owl_line_search_default(self):
+         def f(x, g, *args):
+-            g[0] = 2 * x
+-            return x ** 2
++            g[0] = 2 * x[0]
++            return x[0] ** 2
+ 
+         with pytest.warns(UserWarning, match="OWL-QN"):
+             xmin = fmin_lbfgs(f, 100., orthantwise_c=1)
+     
+     def test_owl_line_search_warning_explicit(self):
+         def f(x, g, *args):
+-            g[0] = 2 * x
+-            return x ** 2
++            g[0] = 2 * x[0]
++            return x[0] ** 2
+ 
+         with pytest.warns(UserWarning, match="OWL-QN"):
+             xmin = fmin_lbfgs(f, 100., orthantwise_c=1, line_search='default')