diff --git a/CHANGELOG.md b/CHANGELOG.md
index 2b656515..a93aa893 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -6,6 +6,7 @@ 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]
+* Add `pillow` as a dev requirement (@lwasser, #253)
 * Removed the `m2r` package from MatPlotCheck (@nkorinek, #247)
 * Made `assert_string_contains()` accept a string instead of a list (@nkorinek, #53)
 * Added functions to get and assert the midpoint values of bins in a histogram (@nkorinek, #184)
diff --git a/dev-requirements.txt b/dev-requirements.txt
index 131f668d..a400be32 100644
--- a/dev-requirements.txt
+++ b/dev-requirements.txt
@@ -10,3 +10,4 @@ setuptools==46.1.3
 pre-commit==1.20.0
 pip==19.0.3
 descartes==1.1.0
+pillow