diff --git a/src/search.cpp b/src/search.cpp
index ef47fd22..c5b4332f 100644
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -1139,7 +1139,7 @@ moves_loop: // When in check, search starts from here
 
       // Castling extension
       if (   type_of(move) == CASTLING
-          && popcount(pos.pieces(us) & ~pos.pieces(PAWN) & (to_sq(move) & KingSide ? KingSide : QueenSide)) <= 3)
+          && popcount(pos.pieces(us) & ~pos.pieces(PAWN) & (to_sq(move) & KingSide ? KingSide : QueenSide)) <= 2)
           extension = 1;
 
       // Late irreversible move extension