diff --git a/lib/src/Utilities.cc b/lib/src/Utilities.cc
index ea68c056b6..0d9f23e9cb 100644
--- a/lib/src/Utilities.cc
+++ b/lib/src/Utilities.cc
@@ -1344,9 +1344,9 @@ std::string secureRandomString(size_t size)
 
     // batch up to 32 bytes of random data for efficiency. Calling
     // secureRandomBytes can be expensive.
+    thread_local trantor::utils::Hash256 hash;
+    thread_local size_t i = 0;
     auto randByte = []() {
-        thread_local trantor::utils::Hash256 hash;
-        thread_local size_t i = 0;
         if (i == 0)
         {
             bool ok = trantor::utils::secureRandomBytes(&hash, sizeof(hash));