diff --git a/src/position.cpp b/src/position.cpp
index bf8497cf..66890a5f 100644
--- a/src/position.cpp
+++ b/src/position.cpp
@@ -100,6 +100,7 @@ CheckInfo::CheckInfo(const Position& pos) {
 void Position::copy(const Position& pos, int th) {
 
   memcpy(this, &pos, sizeof(Position));
+  startState = *st;
   st = &startState;
   threadID = th;
   nodes = 0;