diff --git a/src/search.cpp b/src/search.cpp
index 48694cb2ded..3eb8e9e1ee8 100644
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -173,7 +173,7 @@ namespace {
 void Search::init() {
 
   for (int i = 1; i < MAX_MOVES; ++i)
-      Reductions[i] = int(21.9 * std::log(i));
+      Reductions[i] = int((21.9 + std::log(Threads.size()) / 2) * std::log(i));
 }