diff --git a/ypsu.cpp b/ypsu.cpp
index 1579a9d..76c81e8 100644
--- a/ypsu.cpp
+++ b/ypsu.cpp
@@ -184,7 +184,7 @@
     free(buf);
   }
   void vsort(uint32_t *a, int n) {
-    static thread_local std::vector<uint32_t> bts[256];
+    thread_local std::vector<uint32_t> bts[256];
     for (int shift = 0; shift < 32; shift += 8) {
       for (int i = 0; i < n; i++) bts[a[i] >> shift & 0xff].push_back(a[i]);
       for (int bt = 0, k = 0; bt < 256; bt++) {