diff --git a/gltf/README.md b/gltf/README.md
index a6be1640..ffe6d1e1 100644
--- a/gltf/README.md
+++ b/gltf/README.md
@@ -83,6 +83,7 @@ gltfpack supports most Khronos extensions and some multi-vendor extensions in th
 - KHR_mesh_quantization
 - KHR_texture_basisu
 - KHR_texture_transform
+- EXT_mesh_gpu_instancing
 - EXT_meshopt_compression
 
 Even if the source file does not use extensions, gltfpack may use some extensions in the output file either by default or when certain options are used: