diff --git a/php-binance-api.php b/php-binance-api.php
old mode 100755
new mode 100644
index cf4324a..ffc2dfd
--- a/php-binance-api.php
+++ b/php-binance-api.php
@@ -409,7 +409,14 @@ public function numberOfDecimals($val = 0.00000001)
     public function marketQuoteSell(string $symbol, $quantity, array $flags = [])
     {
         $flags['isQuoteOrder'] = true;
-        $c = $this->numberOfDecimals($this->exchangeInfo()['symbols'][$symbol]['filters'][1]['minQty']);
+        $exchangeInfo = $this->exchangeInfo();
+        $filters = $exchangeInfo['symbols'][$symbol]['filters'];
+        $lotSize = array_filter($filters, function ($filter) {
+            return $filter['filterType'] === 'LOT_SIZE';
+        });
+        $lotSize = array_shift($lotSize);
+        $minQty = $lotSize['minQty'];
+        $c = $this->numberOfDecimals($minQty);
         $quantity = $this->floorDecimal($quantity, $c);
 
         return $this->order("SELL", $symbol, $quantity, 0, "MARKET", $flags);
@@ -445,7 +452,14 @@ public function marketQuoteSellTest(string $symbol, $quantity, array $flags = []
      */
     public function marketSell(string $symbol, $quantity, array $flags = [])
     {
-        $c = $this->numberOfDecimals($this->exchangeInfo()['symbols'][$symbol]['filters'][1]['minQty']);
+        $exchangeInfo = $this->exchangeInfo();
+        $filters = $exchangeInfo['symbols'][$symbol]['filters'];
+        $lotSize = array_filter($filters, function ($filter) {
+            return $filter['filterType'] === 'LOT_SIZE';
+        });
+        $lotSize = array_shift($lotSize);
+        $minQty = $lotSize['minQty'];
+        $c = $this->numberOfDecimals($minQty);
         $quantity = $this->floorDecimal($quantity, $c);
 
         return $this->order("SELL", $symbol, $quantity, 0, "MARKET", $flags);