diff --git a/src/movepick.cpp b/src/movepick.cpp
index a604fe14..e350bda8 100644
--- a/src/movepick.cpp
+++ b/src/movepick.cpp
@@ -239,7 +239,7 @@ void MovePicker::generate_next() {
 
   case KILLERS_S1:
       cur = killers;
-      end = cur + 3;
+      end = cur + 3 - (killers[2].move == killers[0].move || killers[2].move == killers[1].move);
       return;
 
   case QUIETS_1_S1:
diff --git a/src/search.cpp b/src/search.cpp
index 40561544..22183367 100644
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -1092,8 +1092,11 @@ split_point_start: // At split points actual search starts from here
             // Increase history value of the cut-off move
             Value bonus = Value(int(depth) * int(depth));
             Hist.update(pos.piece_moved(bestMove), to_sq(bestMove), bonus);
-            Square prevSq = to_sq((ss-1)->currentMove);
-            Refutation.update(pos.piece_on(prevSq), prevSq, bestMove);
+            if (is_ok((ss-1)->currentMove))
+            {
+                Square prevSq = to_sq((ss-1)->currentMove);
+                Refutation.update(pos.piece_on(prevSq), prevSq, bestMove);
+            }
 
             // Decrease history of all the other played non-capture moves
             for (int i = 0; i < playedMoveCount - 1; i++)