diff --git a/CHANGELOG-PRERELEASE.md b/CHANGELOG-PRERELEASE.md
index 41000c53d..9b71dbaa0 100644
--- a/CHANGELOG-PRERELEASE.md
+++ b/CHANGELOG-PRERELEASE.md
@@ -17,6 +17,7 @@ The format is based on [Keep a Changelog].
 
 ### Fixed
 - Left eye disappears `#493`
+- MergeBone will loose transform information with extreamly small parent scale `#495`
 
 ### Security
 
diff --git a/Editor/Math/Matrix4x4.cs b/Editor/Math/Matrix4x4.cs
index e17355c0d..d0cfe9058 100644
--- a/Editor/Math/Matrix4x4.cs
+++ b/Editor/Math/Matrix4x4.cs
@@ -18,23 +18,27 @@ struct Matrix4x4 : IEquatable<Matrix4x4>
 
         // @formatter:off
         public float m00;
-        public float m01;
-        public float m02;
-        public float m03;
         public float m10;
-        public float m11;
-        public float m12;
-        public float m13;
         public float m20;
-        public float m21;
-        public float m22;
-        public float m23;
         public float m30;
+        public float m01;
+        public float m11;
+        public float m21;
         public float m31;
+        public float m02;
+        public float m12;
+        public float m22;
         public float m32;
+        public float m03;
+        public float m13;
+        public float m23;
         public float m33;
         // @formatter:on
 
+        public Vector3 offset => new Vector3(m03, m13, m23);
+        public Quaternion rotation => ToUnity().rotation;
+        public Vector3 lossyScale => ToUnity().lossyScale;
+
         public Vector3 MultiplyPoint3x4(Vector3 point)
         {
             Vector3 vector3;
@@ -156,5 +160,8 @@ public Matrix4x4(Vector4 column0, Vector4 column1, Vector4 column2, Vector4 colu
         public override bool Equals(object obj) => obj is Matrix4x4 other && Equals(other);
         public override int GetHashCode() => ToUnity().GetHashCode();
         public override string ToString() => ToUnity().ToString();
+
+        public static Matrix4x4 TRS(Vector3 pos, Quaternion rot, Vector3 scale) => UnityMatrix4x4.TRS(pos, rot, scale);
+        public static Matrix4x4 TRS(Transform t) => UnityMatrix4x4.TRS(t.localPosition, t.localRotation, t.localScale);
     }
 }
\ No newline at end of file
diff --git a/Editor/Processors/MergeBoneProcessor.cs b/Editor/Processors/MergeBoneProcessor.cs
index fe6a12c44..5b9e0e5d9 100644
--- a/Editor/Processors/MergeBoneProcessor.cs
+++ b/Editor/Processors/MergeBoneProcessor.cs
@@ -80,11 +80,15 @@ public void Process(OptimizerSession session)
                 // if intermediate objects are inactive, moved bone should be initially inactive
                 // animations are not performed correctly but if bones activity is animated, automatic 
                 // merge bone doesn't merge such bone so ignore that for manual merge bone.
-                var (activeSelf, namePrefix) = ActiveSelfAndNamePrefix(mapping, mapped);
+                var (activeSelf, namePrefix, matrix) = ComputeParentInformation(mapping, mapped);
                 foreach (var child in mapping.DirectChildrenEnumerable().ToArray())
                 {
                     if (mergeMapping.ContainsKey(child)) continue;
+                    var mat = matrix * Matrix4x4.TRS(child);
                     child.parent = mapped;
+                    child.localPosition = mat.offset;
+                    child.localRotation = mat.rotation;
+                    child.localScale = mat.lossyScale;
                     if (!activeSelf) child.gameObject.SetActive(false);
                     if (avoidNameConflict)
                         child.name = namePrefix + "$" + child.name + "$" + (counter++);
@@ -95,19 +99,21 @@ public void Process(OptimizerSession session)
                 if (pair)
                     Object.DestroyImmediate(pair.gameObject);
 
-            (bool activeSelf, string namePrefix) ActiveSelfAndNamePrefix(Transform transform, Transform parent)
+            (bool activeSelf, string namePrefix, Matrix4x4 matrix) ComputeParentInformation(Transform transform, Transform parent)
             {
                 var segments = new List<string>();
                 var activeSelf = true;
+                var matrix = Matrix4x4.identity;
                 for (; transform != parent; transform = transform.parent)
                 {
                     segments.Add(transform.name);
                     activeSelf &= transform.gameObject.activeSelf;
+                    matrix = Matrix4x4.TRS(transform) * matrix;
                 }
 
                 segments.Reverse();
 
-                return (activeSelf, string.Join("$", segments));
+                return (activeSelf, string.Join("$", segments), matrix);
             }
         }