diff --git a/changelog.d/20260730_180321_mgorny.rst b/changelog.d/20260730_180321_mgorny.rst
new file mode 100644
index 0000000..8fcceec
--- /dev/null
+++ b/changelog.d/20260730_180321_mgorny.rst
@@ -0,0 +1,4 @@
+Changed
+-------
+
+*   Include documentation, tests and auxiliary files in the source distribution. (:issue:`12`)
diff --git a/pyproject.toml b/pyproject.toml
index 941ff3e..28349f0 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -74,6 +74,19 @@ enable_error_code = [
 warn_unreachable = true
 
 
+# poetry-core
+# -----------
+
+[tool.poetry]
+include = [
+    { path = ".gitignore", format = "sdist" },
+    { path = "CHANGELOG.rst", format = "sdist" },
+    { path = "docs/", format = "sdist" },
+    { path = "requirements/", format = "sdist" },
+    { path = "tests/", format = "sdist" },
+    { path = "tox.ini", format = "sdist" },
+]
+
 # pytest
 # ------