diff --git a/src/search.cpp b/src/search.cpp
index c7b00766..593fdc72 100644
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -779,7 +779,7 @@ namespace {
         && (ss-1)->statScore < 17329
         &&  eval >= beta
         &&  eval >= ss->staticEval
-        &&  ss->staticEval >= beta - 21 * depth - improvement * 99 / 1300 + 258
+        &&  ss->staticEval >= beta - 21 * depth - improvement / 13 + 258
         && !excludedMove
         &&  pos.non_pawn_material(us)
         && (ss->ply >= thisThread->nmpMinPly))