diff --git a/pyproject.toml b/pyproject.toml
index 6c3aea4d..a313eafb 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -12,9 +12,10 @@ repository = "https://github.com/sdispater/tomlkit"
 
 packages = [
     {include = "tomlkit"},
-    {include = "tests", format = "sdist"}
 ]
 
+include = [{ path = "tests", format = "sdist" }]
+
 [tool.poetry.dependencies]
 python = "~2.7 || ^3.5"