diff --git a/src/movegen.cpp b/src/movegen.cpp
index b4a9d27b..76a27d9f 100644
--- a/src/movegen.cpp
+++ b/src/movegen.cpp
@@ -29,7 +29,7 @@ namespace {
   ExtMove* generate_castling(const Position& pos, ExtMove* moveList) {
 
     constexpr CastlingRight Cr = Us | Cs;
-    constexpr bool KingSide = (Cr == WHITE_OO || Cr == BLACK_OO);
+    constexpr bool KingSide = (Cs == KING_SIDE);
 
     if (pos.castling_impeded(Cr) || !pos.can_castle(Cr))
         return moveList;