diff --git a/game/board.cpp b/game/board.cpp
index 5bde1ad..cd7286e 100644
--- a/game/board.cpp
+++ b/game/board.cpp
@@ -94,9 +94,7 @@ bool Board::isJoker(int iRow, int iCol) const
 
 bool Board::isVacant(int iRow, int iCol) const
 {
-    ASSERT(iRow >= 1 && (unsigned)iRow <= m_layout.getRowCount() &&
-           iCol >= 1 && (unsigned)iCol <= m_layout.getColCount(),
-           "Invalid coordinates");
+    ASSERT(m_layout.isValidCoord(iRow, iCol), "Invalid coordinates");
     return m_tilesRow[iRow][iCol].isEmpty();
 }
 
diff --git a/game/board_layout.h b/game/board_layout.h
index 7632e4f..fa52cc3 100644
--- a/game/board_layout.h
+++ b/game/board_layout.h
@@ -34,6 +34,8 @@ class BoardLayout
 public:
     BoardLayout();
 
+    bool isValidCoord(unsigned iRow, unsigned iCol) const;
+
     unsigned getRowCount() const;
     unsigned getColCount() const;
     int getWordMultiplier(unsigned iRow, unsigned iCol) const;
@@ -48,8 +50,6 @@ private:
     Matrix<int> m_wordMultipliers;
     Matrix<int> m_tileMultipliers;
 
-    bool isValidCoord(unsigned iRow, unsigned iCol) const;
-
     void setDefaultLayout();
 
 };