diff --git a/src/ai/movegen.cpp b/src/ai/movegen.cpp
index d352e046..9fdfee8d 100644
--- a/src/ai/movegen.cpp
+++ b/src/ai/movegen.cpp
@@ -150,7 +150,7 @@ int StateInfo::generateMoves(Stack<move_t, MOVE_COUNT> &moves)
         for (int i = Board::MOVE_PRIORITY_TABLE_SIZE - 1; i >= 0; i--) {
             square = static_cast<square_t>(MoveList::movePriorityTable[i]);
             if (boardLocations[square] & opponent) {
-                if (rule.allowRemoveMill || !position->board.inHowManyMills(square)) {
+                if (rule.allowRemoveMill || !position->board.inHowManyMills(square, PLAYER_NOBODY)) {
                     moves.push_back((move_t)-square);
                 }
             }
diff --git a/src/game/board.cpp b/src/game/board.cpp
index 3ec16e53..34b2e5eb 100644
--- a/src/game/board.cpp
+++ b/src/game/board.cpp
@@ -197,25 +197,14 @@ square_t Board::polarToSquare(int r, int s)
     return static_cast<square_t>(r * N_SEATS + s - 1);
 }
 
-int Board::inHowManyMills(square_t square)
-{
-    int n = 0;
-
-    for (int l = 0; l < LINE_TYPES_COUNT; l++) {
-        if ((locations[square] & 0x30) &
-            locations[millTable[square][l][0]] &
-            locations[millTable[square][l][1]]) {
-            n++;
-        }
-    }
-
-    return n;
-}
-
 int Board::inHowManyMills(square_t square, player_t player)
 {
     int n = 0;
 
+    if (player == PLAYER_NOBODY) {
+        player = player_t(locations[square] & 0x30);
+    }
+
     for (int l = 0; l < LINE_TYPES_COUNT; l++) {
         if (player &
             locations[millTable[square][l][0]] &
@@ -306,7 +295,7 @@ bool Board::isAllInMills(player_t player)
 {
     for (square_t i = SQ_BEGIN; i < SQ_END; i = static_cast<square_t>(i + 1)) {
         if (locations[i] & (uint8_t)player) {
-            if (!inHowManyMills(i)) {
+            if (!inHowManyMills(i, PLAYER_NOBODY)) {
                 return false;
             }
         }
diff --git a/src/game/board.h b/src/game/board.h
index ca00d9d9..c8e8a913 100644
--- a/src/game/board.h
+++ b/src/game/board.h
@@ -69,7 +69,6 @@ public:
     void rotate(int degrees, vector<string> &cmdlist, char *cmdline, int32_t move_, square_t square, bool cmdChange = true);
 
     // 判断棋盘 square 处的棋子处于几个“三连”中
-    int inHowManyMills(square_t square);
     int inHowManyMills(square_t square, player_t player);
 
     // 判断玩家的所有棋子是否都处于“三连”状态
diff --git a/src/game/position.cpp b/src/game/position.cpp
index 1b2f8084..a9ae69a4 100644
--- a/src/game/position.cpp
+++ b/src/game/position.cpp
@@ -573,7 +573,7 @@ bool StateInfo::capture(square_t square, int8_t updateCmdlist)
 
     // 如果当前子是否处于“三连”之中，且对方还未全部处于“三连”之中
     if (!rule.allowRemoveMill &&
-        position->board.inHowManyMills(square) &&
+        position->board.inHowManyMills(square, PLAYER_NOBODY) &&
         !position->board.isAllInMills(opponent)) {
         return false;
     }