diff --git a/src/all_moves_functions.cpp b/src/all_moves_functions.cpp
index 000927f..34e0a2f 100644
--- a/src/all_moves_functions.cpp
+++ b/src/all_moves_functions.cpp
@@ -184,7 +184,7 @@ void _get_all_moves_king(int pos, std::vector<int> *pns, std::array<PieceType, 1
 		if (castle_perms & CastlePerms::WKS){
 			_king_add_if_not_blocked(pos+2, pos, pns, board, pc, rc, right_castle, 1);
 		}
-		if (castle_perms & CastlePerms::WQS){
+		if (castle_perms & CastlePerms::WQS && (*board)[pos-3] == PieceType::NONE){
 			_king_add_if_not_blocked(pos-2, pos, pns, board, pc, rc, left_castle, 1);
 		}
 	} else {
@@ -193,7 +193,7 @@ void _get_all_moves_king(int pos, std::vector<int> *pns, std::array<PieceType, 1
 		if (castle_perms & CastlePerms::BKS){
 			_king_add_if_not_blocked(pos+2, pos, pns, board, pc, rc, right_castle, 1);
 		}
-		if (castle_perms & CastlePerms::BQS){
+		if (castle_perms & CastlePerms::BQS && (*board)[pos-3] == PieceType::NONE){
 			_king_add_if_not_blocked(pos-2, pos, pns, board, pc, rc, left_castle, 1);
 		}
 	}
diff --git a/src/functions.cpp b/src/functions.cpp
index 8837f4c..79158e2 100644
--- a/src/functions.cpp
+++ b/src/functions.cpp
@@ -192,6 +192,7 @@ std::array<PieceType, 120> dumb_move(int move, std::array<PieceType, 120> board)
 	std::array<PieceType, 120> new_board;
 	std::copy(std::begin(board), std::end(board), std::begin(new_board));
 	int en_passant_flag = get_en_pass_flag(move);
+	int castle_flag = get_castle_flag(move);
 	int from = get_from_sq(move);
 	int to = get_to_sq(move);
 	PieceType piece = new_board[from];
@@ -210,7 +211,25 @@ std::array<PieceType, 120> dumb_move(int move, std::array<PieceType, 120> board)
 		new_board[other_pawn_pos] = PieceType::NONE;
 		new_board[to] = piece;
 		new_board[from] = PieceType::NONE;
-	} else {
+	} else if(castle_flag == 1){
+		int diff = to-from;
+		int rook_from_pos = 0;
+		int rook_to_pos = 0;
+		// If castling queenside
+		if (diff == -2){
+			rook_from_pos = to-2;
+			rook_to_pos = from-1;
+		// If caslting kingside
+		} else if (diff == 2){
+			rook_from_pos = to+1;
+			rook_to_pos = from+1;
+		}
+		PieceType rook_pt = new_board[rook_from_pos];
+		new_board[rook_from_pos] = PieceType::NONE;
+		new_board[rook_to_pos] = rook_pt;
+		new_board[from] = PieceType::NONE;
+		new_board[to] = piece;
+       	} else {
 		new_board[to] = piece;
 		new_board[from] = PieceType::NONE;
 	}
diff --git a/tests/main.cpp b/tests/main.cpp
index 70ea985..a358a75 100644
--- a/tests/main.cpp
+++ b/tests/main.cpp
@@ -153,6 +153,11 @@ TEST_CASE("Test for castling moves.", "[get_all_moves]"){
 	auto bcast_checked_moves = get_all_moves(BCASTLING_POS, CASTLING_CHECK_BOARD, true, 0, 0xF);
 	CHECK(get_to_squares(bcast_checked_moves) == BCASTLING_CHECK_MOVES);
 	CHECK(get_castle_flags(bcast_checked_moves) == checked_cast_flags);
+	// Check that castling moves are not allowed when the rook is blocked.
+	auto blocked_castling_moves = get_all_moves(CASTLE_BLOCKED_POS, CASTLE_BLOCKED_BOARD, true, 0, 0xF);
+	CHECK(get_to_squares(blocked_castling_moves) == CASTLE_BLOCKED_MOVES);
+	auto blocked_castling_qmoves = get_all_moves(CASTLE_BLOCKED_QPOS, CASTLE_BLOCKED_QBOARD, true, 0, 0xF);
+	CHECK(get_to_squares(blocked_castling_qmoves) == CASTLE_BLOCKED_QMOVES);
 }
 
 TEST_CASE("Test that en passant moves are properly handled by dumb_move", "dumb_move"){
@@ -161,3 +166,10 @@ TEST_CASE("Test that en passant moves are properly handled by dumb_move", "dumb_
 	CHECK(dumb_move(make_move(EN_PASSANT_CHECK_POS2, EN_PASSANT_EN_PASSANT_SQUARE2, PieceType::B_PAWN, PieceType::NONE, 1), EN_PASSANT_CHECK_BOARD2) == EN_PASSANT_CHECK_MOVED_BOARD2);
 	CHECK(dumb_move(make_move(EN_PASSANT_CHECK_POS3, EN_PASSANT_EN_PASSANT_SQUARE3, PieceType::B_PAWN, PieceType::NONE, 1), EN_PASSANT_CHECK_BOARD3) == EN_PASSANT_CHECK_MOVED_BOARD3);
 }
+
+TEST_CASE("Test that castle moves are poperly handled by dumb_mobe", "[dumb_move]"){
+	CHECK(dumb_move(make_move(CASTLE_FROM_POS, CASTLE_TO_POS, PieceType::NONE, PieceType::NONE, 0, 0, 1), CASTLE_BOARD) == CASTLE_BOARD_WK);
+	CHECK(dumb_move(make_move(CASTLE_FROM_QPOS, CASTLE_TO_QPOS, PieceType::NONE, PieceType::NONE, 0, 0, 1), CASTLE_BOARD) == CASTLE_BOARD_WQ);
+	CHECK(dumb_move(make_move(BCASTLE_FROM_POS, BCASTLE_TO_POS, PieceType::NONE, PieceType::NONE, 0, 0, 1), CASTLE_BOARD) == CASTLE_BOARD_BK);
+	CHECK(dumb_move(make_move(BCASTLE_FROM_QPOS, BCASTLE_TO_QPOS, PieceType::NONE, PieceType::NONE, 0, 0, 1), CASTLE_BOARD) == CASTLE_BOARD_BQ);
+}
diff --git a/tests/valid_moves.h b/tests/valid_moves.h
index 0fe497c..32c970c 100644
--- a/tests/valid_moves.h
+++ b/tests/valid_moves.h
@@ -311,6 +311,128 @@ const int BLACK_CHECK_POS2 = F8;
 const std::vector<int> BCASTLING_CHECK_MOVES = {
 	D7, E7, F7
 };
+// Check that the dumb_move function actually moves the rook and the king to the right squares.
+const int CASTLE_FROM_POS = E1;
+const int CASTLE_TO_POS = G1;
+const int BCASTLE_FROM_POS = E8;
+const int BCASTLE_TO_POS = G8;
+
+const int CASTLE_FROM_QPOS = E1;
+const int CASTLE_TO_QPOS = C1;
+const int BCASTLE_FROM_QPOS = E8;
+const int BCASTLE_TO_QPOS = C8;
+
+const std::array<PieceType, 120> CASTLE_BOARD = {
+	INV, INV, INV, INV, INV, INV, INV, INV, INV, INV, 	
+	INV, INV, INV, INV, INV, INV, INV, INV, INV, INV, 	
+	INV, B_ROOK, NONE, NONE, NONE, B_KING, NONE, NONE, B_ROOK,  INV,	
+	INV, NONE, NONE, NONE, NONE, NONE, NONE, NONE, NONE,  INV,	
+	INV, NONE, NONE, NONE, NONE, NONE, NONE, NONE, NONE,  INV,	
+	INV, NONE, NONE, NONE, NONE, NONE, NONE, NONE, NONE, INV,
+	INV, NONE, NONE, NONE, NONE, NONE, NONE, NONE, NONE,  INV,	
+	INV, NONE, NONE, NONE, NONE, NONE, NONE, NONE, NONE,  INV,	
+	INV, NONE, NONE, NONE, NONE, NONE, NONE, NONE, NONE,  INV,	
+	INV, W_ROOK, NONE, NONE, NONE, W_KING, NONE, NONE, W_ROOK, INV,
+	INV, INV, INV, INV, INV, INV, INV, INV, INV, INV, 	
+	INV, INV, INV, INV, INV, INV, INV, INV, INV, INV	
+};
+const std::array<PieceType, 120> CASTLE_BOARD_WK = {
+	INV, INV, INV, INV, INV, INV, INV, INV, INV, INV, 	
+	INV, INV, INV, INV, INV, INV, INV, INV, INV, INV, 	
+	INV, B_ROOK, NONE, NONE, NONE, B_KING, NONE, NONE, B_ROOK,  INV,	
+	INV, NONE, NONE, NONE, NONE, NONE, NONE, NONE, NONE,  INV,	
+	INV, NONE, NONE, NONE, NONE, NONE, NONE, NONE, NONE,  INV,	
+	INV, NONE, NONE, NONE, NONE, NONE, NONE, NONE, NONE, INV,
+	INV, NONE, NONE, NONE, NONE, NONE, NONE, NONE, NONE,  INV,	
+	INV, NONE, NONE, NONE, NONE, NONE, NONE, NONE, NONE,  INV,	
+	INV, NONE, NONE, NONE, NONE, NONE, NONE, NONE, NONE,  INV,	
+	INV, W_ROOK, NONE, NONE, NONE, NONE, W_ROOK, W_KING, NONE, INV,
+	INV, INV, INV, INV, INV, INV, INV, INV, INV, INV, 	
+	INV, INV, INV, INV, INV, INV, INV, INV, INV, INV	
+};
+const std::array<PieceType, 120> CASTLE_BOARD_BK = {
+	INV, INV, INV, INV, INV, INV, INV, INV, INV, INV, 	
+	INV, INV, INV, INV, INV, INV, INV, INV, INV, INV, 	
+	INV, B_ROOK, NONE, NONE, NONE, NONE, B_ROOK, B_KING, NONE,  INV,	
+	INV, NONE, NONE, NONE, NONE, NONE, NONE, NONE, NONE,  INV,	
+	INV, NONE, NONE, NONE, NONE, NONE, NONE, NONE, NONE,  INV,	
+	INV, NONE, NONE, NONE, NONE, NONE, NONE, NONE, NONE, INV,
+	INV, NONE, NONE, NONE, NONE, NONE, NONE, NONE, NONE,  INV,	
+	INV, NONE, NONE, NONE, NONE, NONE, NONE, NONE, NONE,  INV,	
+	INV, NONE, NONE, NONE, NONE, NONE, NONE, NONE, NONE,  INV,	
+	INV, W_ROOK, NONE, NONE, NONE, W_KING, NONE, NONE, W_ROOK, INV,
+	INV, INV, INV, INV, INV, INV, INV, INV, INV, INV, 	
+	INV, INV, INV, INV, INV, INV, INV, INV, INV, INV	
+};
+const std::array<PieceType, 120> CASTLE_BOARD_WQ = {
+	INV, INV, INV, INV, INV, INV, INV, INV, INV, INV, 	
+	INV, INV, INV, INV, INV, INV, INV, INV, INV, INV, 	
+	INV, B_ROOK, NONE, NONE, NONE, B_KING, NONE, NONE, B_ROOK,  INV,	
+	INV, NONE, NONE, NONE, NONE, NONE, NONE, NONE, NONE,  INV,	
+	INV, NONE, NONE, NONE, NONE, NONE, NONE, NONE, NONE,  INV,	
+	INV, NONE, NONE, NONE, NONE, NONE, NONE, NONE, NONE, INV,
+	INV, NONE, NONE, NONE, NONE, NONE, NONE, NONE, NONE,  INV,	
+	INV, NONE, NONE, NONE, NONE, NONE, NONE, NONE, NONE,  INV,	
+	INV, NONE, NONE, NONE, NONE, NONE, NONE, NONE, NONE,  INV,	
+	INV, NONE, NONE, W_KING, W_ROOK, NONE, NONE, NONE, W_ROOK, INV,
+	INV, INV, INV, INV, INV, INV, INV, INV, INV, INV, 	
+	INV, INV, INV, INV, INV, INV, INV, INV, INV, INV	
+};
+const std::array<PieceType, 120> CASTLE_BOARD_BQ = {
+	INV, INV, INV, INV, INV, INV, INV, INV, INV, INV, 	
+	INV, INV, INV, INV, INV, INV, INV, INV, INV, INV, 	
+	INV, NONE, NONE, B_KING, B_ROOK, NONE, NONE, NONE, B_ROOK,  INV,	
+	INV, NONE, NONE, NONE, NONE, NONE, NONE, NONE, NONE,  INV,	
+	INV, NONE, NONE, NONE, NONE, NONE, NONE, NONE, NONE,  INV,	
+	INV, NONE, NONE, NONE, NONE, NONE, NONE, NONE, NONE, INV,
+	INV, NONE, NONE, NONE, NONE, NONE, NONE, NONE, NONE,  INV,	
+	INV, NONE, NONE, NONE, NONE, NONE, NONE, NONE, NONE,  INV,	
+	INV, NONE, NONE, NONE, NONE, NONE, NONE, NONE, NONE,  INV,	
+	INV, W_ROOK, NONE, NONE, NONE, W_KING, NONE, NONE, W_ROOK, INV,
+	INV, INV, INV, INV, INV, INV, INV, INV, INV, INV, 	
+	INV, INV, INV, INV, INV, INV, INV, INV, INV, INV	
+};
+
+// Check that castling is disallowed when there is a piece blocking the rook queenside.
+const int CASTLE_BLOCKED_POS = E1;
+const std::array<PieceType, 120> CASTLE_BLOCKED_BOARD = {
+	INV, INV, INV, INV, INV, INV, INV, INV, INV, INV, 	
+	INV, INV, INV, INV, INV, INV, INV, INV, INV, INV, 	
+	INV, B_ROOK, NONE, NONE, NONE, B_KING, NONE, NONE, B_ROOK,  INV,	
+	INV, NONE, NONE, NONE, NONE, NONE, NONE, NONE, NONE,  INV,	
+	INV, NONE, NONE, NONE, NONE, NONE, NONE, NONE, NONE,  INV,	
+	INV, NONE, NONE, NONE, NONE, NONE, NONE, NONE, NONE, INV,
+	INV, NONE, NONE, NONE, NONE, NONE, NONE, NONE, NONE,  INV,	
+	INV, NONE, NONE, NONE, NONE, NONE, NONE, NONE, NONE,  INV,	
+	INV, NONE, NONE, NONE, NONE, NONE, NONE, NONE, NONE,  INV,	
+	INV, W_ROOK, W_KNIGHT, NONE, NONE, W_KING, NONE, NONE, W_ROOK, INV,
+	INV, INV, INV, INV, INV, INV, INV, INV, INV, INV, 	
+	INV, INV, INV, INV, INV, INV, INV, INV, INV, INV	
+};
+const std::vector<int> CASTLE_BLOCKED_MOVES = {
+	D2, E2, F2,
+	F1, D1, G1
+};
+
+const int CASTLE_BLOCKED_QPOS = E8;
+const std::array<PieceType, 120> CASTLE_BLOCKED_QBOARD = {
+	INV, INV, INV, INV, INV, INV, INV, INV, INV, INV, 	
+	INV, INV, INV, INV, INV, INV, INV, INV, INV, INV, 	
+	INV, B_ROOK, B_KNIGHT, NONE, NONE, B_KING, NONE, NONE, B_ROOK,  INV,	
+	INV, NONE, NONE, NONE, NONE, NONE, NONE, NONE, NONE,  INV,	
+	INV, NONE, NONE, NONE, NONE, NONE, NONE, NONE, NONE,  INV,	
+	INV, NONE, NONE, NONE, NONE, NONE, NONE, NONE, NONE, INV,
+	INV, NONE, NONE, NONE, NONE, NONE, NONE, NONE, NONE,  INV,	
+	INV, NONE, NONE, NONE, NONE, NONE, NONE, NONE, NONE,  INV,	
+	INV, NONE, NONE, NONE, NONE, NONE, NONE, NONE, NONE,  INV,	
+	INV, W_ROOK, W_KNIGHT, NONE, NONE, W_KING, NONE, NONE, W_ROOK, INV,
+	INV, INV, INV, INV, INV, INV, INV, INV, INV, INV, 	
+	INV, INV, INV, INV, INV, INV, INV, INV, INV, INV	
+};
+const std::vector<int> CASTLE_BLOCKED_QMOVES = {
+	D7, E7, F7,
+	F8, D8, G8
+};
 
 // Check tests for king