diff --git a/src/search.cpp b/src/search.cpp
index ff10ba5d..0d290eec 100644
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -358,7 +358,7 @@ namespace {
                 else
                     break;
 
-                delta += delta / 2;
+                delta += 3 * delta / 8;
 
                 assert(alpha >= -VALUE_INFINITE && beta <= VALUE_INFINITE);
             }