diff --git a/quinn/experimental/__init__.py b/quinn/experimental/__init__.py
new file mode 100644
index 00000000..89f0d708
--- /dev/null
+++ b/quinn/experimental/__init__.py
@@ -0,0 +1,7 @@
+"""Experimental API.
+
+These APIs are unstable because they use non-stable parts of PySpark API.
+"""
+
+from quinn.experimental.plan_utils import estimate_size_of_df  # noqa: F401, I001
+from quinn.experimental.plan_utils import get_plan_from_df  # noqa: F401
diff --git a/quinn/plan_utils.py b/quinn/experimental/plan_utils.py
similarity index 100%
rename from quinn/plan_utils.py
rename to quinn/experimental/plan_utils.py