diff --git a/pyproject.toml b/pyproject.toml
index 6cc79d965446753f10ab0847338bfee395e5ab48..bbba969b0df35c20f26dcd7c323277ac5c1cf9b8 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -37,8 +37,8 @@ classifiers=[
 keywords = ['machine learning, supervised learning, classification, ensemble methods, boosting, kernel']
 
 [project.optional-dependencies]
-test = ['pytest', 'coverage==4.5.3', 'pytest-cov']
-doc = ['sphinx==5.0', 'numpydoc', 'sphinx_gallery', 'matplotlib', 'sphinx_rtd_theme"']
+test = ["pytest", "coverage==4.5.3", "pytest-cov"]
+doc = ["sphinx==5.0", "numpydoc", "sphinx_gallery", "matplotlib", "sphinx_rtd_theme"]
 
 [project.urls]
 Homepage = 'https://github.com/multi-learn/scikit-multimodallearn'