diff --git a/CHANGELOG.md b/CHANGELOG.md
index 449b7ba4..ed779443 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -3,6 +3,11 @@
 All notable changes to this project will be documented in this file.
 This project adheres to [Semantic Versioning](http://semver.org/).
 
+## [5.0.0] - UNRELEASED
+
+### Updated
+- updated to GLTFast 6.0.1 by @harrisonhough in [#XXX]()
+
 ## [4.0.1] - 2023.11.14
 
 ### Fixed
diff --git a/Runtime/GLTF/GltFastGameObjectInstantiator.cs b/Runtime/GLTF/GltFastGameObjectInstantiator.cs
index 30f53400..5d688e14 100644
--- a/Runtime/GLTF/GltFastGameObjectInstantiator.cs
+++ b/Runtime/GLTF/GltFastGameObjectInstantiator.cs
@@ -23,8 +23,7 @@ public GltFastGameObjectInstantiator(
         public override void AddPrimitive(
             uint nodeIndex,
             string meshName,
-            Mesh mesh,
-            int[] materialIndices,
+            MeshResult meshResult,
             uint[] joints = null,
             uint? rootJoint = null,
             float[] morphTargetWeights = null,
@@ -53,18 +52,18 @@ public override void AddPrimitive(
 
             Renderer renderer;
 
-            var hasMorphTargets = mesh.blendShapeCount > 0;
+            var hasMorphTargets = meshResult.mesh.blendShapeCount > 0;
             if (joints == null && !hasMorphTargets)
             {
-                var meshFilter = meshGo.AddComponent<MeshFilter>();
-                meshFilter.mesh = mesh;
-                var meshRenderer = meshGo.AddComponent<MeshRenderer>();
-                renderer = meshRenderer;
+                var mf = meshGo.AddComponent<MeshFilter>();
+                mf.mesh = meshResult.mesh;
+                var mr = meshGo.AddComponent<MeshRenderer>();
+                renderer = mr;
             }
             else
             {
-                var skinnedMeshRenderer = meshGo.AddComponent<SkinnedMeshRenderer>();
-                skinnedMeshRenderer.updateWhenOffscreen = m_Settings.SkinUpdateWhenOffscreen;
+                var smr = meshGo.AddComponent<SkinnedMeshRenderer>();
+                smr.updateWhenOffscreen = m_Settings.SkinUpdateWhenOffscreen;
                 if (joints != null)
                 {
                     var bones = new Transform[joints.Length];
@@ -73,28 +72,28 @@ public override void AddPrimitive(
                         var jointIndex = joints[j];
                         bones[j] = m_Nodes[jointIndex].transform;
                     }
-                    skinnedMeshRenderer.bones = bones;
+                    smr.bones = bones;
                     if (rootJoint.HasValue)
                     {
-                        skinnedMeshRenderer.rootBone = m_Nodes[rootJoint.Value].transform;
+                        smr.rootBone = m_Nodes[rootJoint.Value].transform;
                     }
                 }
-                skinnedMeshRenderer.sharedMesh = mesh;
+                smr.sharedMesh = meshResult.mesh;
                 if (morphTargetWeights != null)
                 {
                     for (var i = 0; i < morphTargetWeights.Length; i++)
                     {
                         var weight = morphTargetWeights[i];
-                        skinnedMeshRenderer.SetBlendShapeWeight(i, weight);
+                        smr.SetBlendShapeWeight(i, weight);
                     }
                 }
-                renderer = skinnedMeshRenderer;
+                renderer = smr;
             }
 
-            var materials = new Material[materialIndices.Length];
+            var materials = new Material[meshResult.materialIndices.Length];
             for (var index = 0; index < materials.Length; index++)
             {
-                Material material = m_Gltf.GetMaterial(materialIndices[index]) ?? m_Gltf.GetDefaultMaterial();
+                var material = m_Gltf.GetMaterial(meshResult.materialIndices[index]) ?? m_Gltf.GetDefaultMaterial();
                 materials[index] = material;
             }
 
diff --git a/package.json b/package.json
index 253910bb..71630a4d 100644
--- a/package.json
+++ b/package.json
@@ -9,7 +9,7 @@
   "changelogUrl": "https://github.com/readyplayerme/rpm-unity-sdk-core/blob/main/CHANGELOG.md",
   "licensesUrl": "https://github.com/readyplayerme/rpm-unity-sdk-core/blob/main/LICENSE.md",
   "dependencies": {
-    "com.unity.cloud.gltfast": "5.0.4",
+    "com.unity.cloud.gltfast": "6.0.1",
     "com.unity.nuget.newtonsoft-json": "3.0.2"
   },
   "keywords": [