diff --git a/deptry/imports_to_package_names.py b/deptry/imports_to_package_names.py
index 5dee2e47..d161cb62 100644
--- a/deptry/imports_to_package_names.py
+++ b/deptry/imports_to_package_names.py
@@ -50,7 +50,7 @@ def convert(self, imported_modules: List[str]) -> List[str]:
 
         return packages
 
-    def _get_stdlib_packages(self) -> set[str]:
+    def _get_stdlib_packages(self):
         incorrect_version_error = ValueError(
             f"Incorrect Python version {'.'.join([str(x) for x in sys.version_info[0:3]])}. Only 3.7, 3.8, 3.9 and 3.10 are currently supported."
         )
diff --git a/pyproject.toml b/pyproject.toml
index be231519..0575a142 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -24,7 +24,6 @@ mkdocs = "^1.3.0"
 mkdocs-material = "^8.3.8"
 mkdocstrings = "^0.18.1"
 mypy = "^0.961"
-types-toml = "^0.10.8"
 
 [build-system]
 requires = ["poetry-core>=1.0.0"]