diff --git a/setup.py b/setup.py
index b41b95b3..7a19394c 100644
--- a/setup.py
+++ b/setup.py
@@ -26,7 +26,7 @@ setup(name='pyerrors',
       packages=find_packages(),
       python_requires='>=3.8.0',
       install_requires=['numpy>=1.24', 'autograd>=1.6.2', 'numdifftools>=0.9.41', 'matplotlib>=3.7', 'scipy>=1.10', 'iminuit>=2.21', 'h5py>=3.8', 'lxml>=4.9', 'python-rapidjson>=1.10', 'pandas>=2.0'],
-      extras_require={'test': ['pytest', 'pytest-cov', 'pytest-benchmark', 'hypothesis']},
+      extras_require={'test': ['pytest', 'pytest-cov', 'pytest-benchmark', 'hypothesis', 'nbmake']},
       classifiers=[
           'Development Status :: 5 - Production/Stable',
           'Intended Audience :: Science/Research',