diff --git a/pyproject.toml b/pyproject.toml
index 538cbbc8..07d064a3 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -41,7 +41,7 @@ rich = ">=14.0.0, <14.1.0"
 # dayone-only deps
 tzlocal = ">=4.0"   # https://github.com/regebro/tzlocal/blob/master/CHANGES.txt
 
-[tool.poetry.dev-dependencies]
+[tool.poetry.group.dev.dependencies]
 black = { version = ">=21.5b2", allow-prereleases = true }
 ipdb = "*"
 mkdocs = ">=1.4"