diff --git a/src/evaluate.cpp b/src/evaluate.cpp
index 5c56ed66..85665a43 100644
--- a/src/evaluate.cpp
+++ b/src/evaluate.cpp
@@ -43,7 +43,7 @@ namespace {
   const int Sign[2] = { 1, -1 };
 
   // Evaluation grain size, must be a power of 2
-  const int GrainSize = 4;
+  const int GrainSize = 8;
 
   // Evaluation weights, initialized from UCI options
   int WeightMobilityMidgame, WeightMobilityEndgame;