diff --git a/CHANGELOG.md b/CHANGELOG.md
new file mode 100644
index 0000000..c9da54b
--- /dev/null
+++ b/CHANGELOG.md
@@ -0,0 +1,35 @@
+# Changelog
+All notable changes to this project will be documented in this file.
+
+The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
+and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
+
+## [Unreleased]
+### Added
+
+### Changed
+
+### Removed
+
+## [0.13.1] - 2019-08-05
+### Added
+- Adds support for masking variables in their definition, issue #59 [@benkrikler](https://github.com/benkrikler)
+- Adds several constants for variable expressions, issue #21 [@benkrikler](https://github.com/benkrikler)
+- Added this changelog [@benkrikler](https://github.com/benkrikler)
+
+### Changed
+- Use `pandas.groupby(..).counts()` to make binned dataframes, issue #51 [@benkrikler](https://github.com/benkrikler)
+
+### Removed
+
+## [0.13.0] - 2019-07-28
+### Added
+- Add support for multiple output file types for binned dataframes, issue #57 [@asnaylor](https://github.com/asnaylor)
+
+### Changed
+- Fix issue with binned dataframe expressions and multiple similar branch names, issue #60 [@benkrikler](https://github.com/benkrikler)
+- Enable multiple cut-flow stages and make the input chunk.tree have consistent array and arrays methods, issue #61 [@benkrikler](https://github.com/benkrikler)
+
+### Removed
+
+## [0.12.0] - 2019-05-28
diff --git a/tests/selection/test_stage.py b/tests/selection/test_stage.py
index 83611c7..f412cfe 100644
--- a/tests/selection/test_stage.py
+++ b/tests/selection/test_stage.py
@@ -148,3 +148,5 @@ def test_sequential_stages(cutflow_1, select_2, infile, full_event_range, tmpdir
     cutflow_2.event(chunk)
 
     assert len(chunk.tree) == 2
+    jet_py = chunk.tree.array("Jet_Py")
+    assert pytest.approx(jet_py.flatten()) == [49.641838, 45.008915, -78.01798, 60.730812]