diff --git a/pyproject.toml b/pyproject.toml
index 3bc55993a8..3b2a9f3135 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,3 +1,6 @@
+[tool.black]
+line-length = 99
+
 [tool.codespell]
 count = ""
 ignore-regex = '\b[A-Z]{3}\b'