diff --git a/changelog.txt b/changelog.txt
index c9afb51d..a5fdeca2 100644
--- a/changelog.txt
+++ b/changelog.txt
@@ -7,6 +7,7 @@ OPENSEADRAGON CHANGELOG
 * DEPRECATION: The OpenSeadragon.createCallback function is no longer recommended (#2367 @akansjain)
 * The viewer now uses WebGL when available (#2310, #2462, #2466, #2468, #2469, #2472, #2478, #2488, #2492, #2521, #2537 @pearcetm, @Aiosa, @thec0keman)
 * Added webp to supported image formats (#2455 @BeebBenjamin)
+* Added avif to supported image formats (#2439 @msalsbery)
 * Introduced maxTilesPerFrame option to allow loading more tiles simultaneously (#2387 @jetic83)
 * Now when creating a viewer or navigator, we leave its position style alone if possible (#2393 @VIRAT9358)
 * Added getter & setter for Viewport.maxZoomPixelRatio (#2506 @eug-L)
diff --git a/src/openseadragon.js b/src/openseadragon.js
index 66036afa..249d7725 100644
--- a/src/openseadragon.js
+++ b/src/openseadragon.js
@@ -2631,6 +2631,7 @@ function OpenSeadragon( options ){
          * Preexisting formats that are not being updated are left unchanged.
          * By default, the defined formats are
          * <pre><code>{
+         *      avif: true,
          *      bmp:  false,
          *      jpeg: true,
          *      jpg:  true,
@@ -2698,6 +2699,7 @@ function OpenSeadragon( options ){
 
 
     var FILEFORMATS = {
+            avif: true,
             bmp:  false,
             jpeg: true,
             jpg:  true,