diff --git a/.devcontainer/Dockerfile b/.devcontainer/Dockerfile
index 44a7262..46b098b 100644
--- a/.devcontainer/Dockerfile
+++ b/.devcontainer/Dockerfile
@@ -4,7 +4,7 @@
 # License, v. 2.0. If a copy of the MPL was not distributed with this
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
-FROM thehale/python-poetry:1.1.14-py3.8-slim
+FROM thehale/python-poetry:1.3.1-py3.8-slim
 ARG PROJECT_FOLDER_NAME
 ENV PROJECT_ROOT_DIR=/workspaces/$PROJECT_FOLDER_NAME
 
diff --git a/pyproject.toml b/pyproject.toml
index 9cde5b4..d79b576 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -13,7 +13,7 @@ keywords = [ "introspection", "signatures", "functions", "validation" ]
 [tool.poetry.dependencies]
 python = "^3.8"
 
-[tool.poetry.dev-dependencies]
+[tool.poetry.group.dev.dependencies]
 pytest = "^7.2"
 pre-commit = "^2.20.0"
 liccheck = "^0.8.0"