diff --git a/indra/llmath/llvolume.cpp b/indra/llmath/llvolume.cpp
index 47c4977afd..2b23325bff 100644
--- a/indra/llmath/llvolume.cpp
+++ b/indra/llmath/llvolume.cpp
@@ -6821,7 +6821,7 @@ BOOL LLVolumeFace::createSide(LLVolume* volume, BOOL partial_build)
 
 	LLVector4a* norm = mNormals;
 
-	static LLAlignedArray<LLVector4a, 64> triangle_normals;
+    static thread_local LLAlignedArray<LLVector4a, 64> triangle_normals;
     try
     {
         triangle_normals.resize(count);