diff --git a/Assets/UniGLTF/Runtime/Extensions/glTFExtensions.cs b/Assets/UniGLTF/Runtime/Extensions/glTFExtensions.cs
index 2ea4400cd..5ef920f63 100644
--- a/Assets/UniGLTF/Runtime/Extensions/glTFExtensions.cs
+++ b/Assets/UniGLTF/Runtime/Extensions/glTFExtensions.cs
@@ -72,6 +72,10 @@ namespace UniGLTF
             {
                 return cv.ComponentType;
             }
+            else if (typeof(T) == typeof(ushort))
+            {
+                return glComponentType.UNSIGNED_SHORT;
+            }
             else if (typeof(T) == typeof(uint))
             {
                 return glComponentType.UNSIGNED_INT;
@@ -119,10 +123,10 @@ namespace UniGLTF
             }
         }
 
-        public static int ExtendBufferAndGetAccessorIndex<T>(this glTF gltf, int bufferIndex, T[] array,
+        public static int ExtendBufferAndGetAccessorIndex<T>(this glTF gltf, int bufferIndex, IReadOnlyList<T> list,
             glBufferTarget target = glBufferTarget.NONE) where T : struct
         {
-            return gltf.ExtendBufferAndGetAccessorIndex(bufferIndex, new ArraySegment<T>(array), target);
+            return gltf.ExtendBufferAndGetAccessorIndex(bufferIndex, new ArraySegment<T>(list.ToArray()), target);
         }
 
         public static int ExtendBufferAndGetAccessorIndex<T>(this glTF gltf, int bufferIndex,
diff --git a/Assets/UniGLTF/Runtime/UniGLTF/IO/MeshIO/MeshExporter_SharedVertexBuffer.cs b/Assets/UniGLTF/Runtime/UniGLTF/IO/MeshIO/MeshExporter_SharedVertexBuffer.cs
index 192077151..1c4be08d9 100644
--- a/Assets/UniGLTF/Runtime/UniGLTF/IO/MeshIO/MeshExporter_SharedVertexBuffer.cs
+++ b/Assets/UniGLTF/Runtime/UniGLTF/IO/MeshIO/MeshExporter_SharedVertexBuffer.cs
@@ -127,7 +127,7 @@ namespace UniGLTF
                     indices.Add((uint)i0);
                 }
 
-                var indicesAccessorIndex = gltf.ExtendBufferAndGetAccessorIndex(bufferIndex, indices.ToArray(), glBufferTarget.ELEMENT_ARRAY_BUFFER);
+                var indicesAccessorIndex = gltf.ExtendBufferAndGetAccessorIndex(bufferIndex, indices, glBufferTarget.ELEMENT_ARRAY_BUFFER);
                 if (indicesAccessorIndex < 0)
                 {
                     // https://github.com/vrm-c/UniVRM/issues/664