diff --git a/CHANGELOG.md b/CHANGELOG.md
index 6053c71..eaa0ba1 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,7 @@
+## v2.3.1
+### Bug Fixes
+* Fix tangents being 0 if a mesh with no tangents gets merged with one that has tangents.
+
 ## v2.3.0
 ### Features
 * Added tooltips to all toggles and foldouts. They are identical to the descriptions in the readme.
diff --git a/Editor/d4rkAvatarOptimizer.cs b/Editor/d4rkAvatarOptimizer.cs
index 417a94c..ba8c39c 100644
--- a/Editor/d4rkAvatarOptimizer.cs
+++ b/Editor/d4rkAvatarOptimizer.cs
@@ -2422,7 +2422,7 @@ private void CombineAndOptimizeMaterials()
                 newMesh.bounds = mesh.bounds;
                 newMesh.SetNormals(targetNormals);
                 if (targetTangents.Any(t => t != Vector4.zero))
-                    newMesh.SetTangents(targetTangents);
+                    newMesh.SetTangents(targetTangents.Select(t => t == Vector4.zero ? new Vector4(1, 0, 0, 1) : t).ToArray());
                 newMesh.subMeshCount = matchedSlots.Count;
                 for (int i = 0; i < matchedSlots.Count; i++)
                 {
diff --git a/package.json b/package.json
index 7ee95ed..84ca085 100644
--- a/package.json
+++ b/package.json
@@ -1,7 +1,7 @@
 {
   "name": "d4rkpl4y3r.d4rkavataroptimizer",
   "displayName": "d4rkAvatarOptimizer",
-  "version": "2.3.0",
+  "version": "2.3.1",
   "unity": "2019.4",
   "description": "An optimizer aiming to reduce mesh & material count and more of VRChat 3.0 avatars.",
   "dependencies": {},