diff --git a/CHANGELOG.md b/CHANGELOG.md
index a1aefc0755e33ef718bfe82bd8afa9dddc59a3c2..34decc6fa1a3a4acdeef1a4d6c18fad3510a5c81 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -37,6 +37,7 @@ release.
 
 ### Fixed
 - Updated documentation string for `compute_covariance`. [#177](https://github.com/USGS-Astrogeology/plio/pull/177)
+- Improved performance of `to_isis`. [#181](https://github.com/USGS-Astrogeology/plio/issues/181)
 
 ## [1.5.0]()