diff --git a/README.md b/README.md
index 70ac274d..8b28e75c 100644
--- a/README.md
+++ b/README.md
@@ -94,7 +94,7 @@ $writer = Writer::createFromString('john,doe,john.doe@example.com');
 
 Both classes constructors take one optional parameter `$open_mode` representing the file open mode used by the PHP [fopen](http://php.net/manual/en/function.fopen.php) function. 
 * The `Bakame\Csv\Writer` `$open_mode` default value is `w`.
-* The `Bakame\Csv\Reader` `$open_mode` default value is `r`, and **no other value is possible**. So you don't need to explicitly set it.
+* The `Bakame\Csv\Reader` `$open_mode` default value is `r`.
 
 The static method `createFromString` is to be use if your data is a string. This method takes no optional `$open_mode` parameter.
 
diff --git a/src/AbstractCsv.php b/src/AbstractCsv.php
index 614f5c5e..6c1b258b 100644
--- a/src/AbstractCsv.php
+++ b/src/AbstractCsv.php
@@ -96,13 +96,6 @@ class AbstractCsv implements JsonSerializable, IteratorAggregate
      */
     protected $encoding = 'UTF-8';
 
-    /**
-     * Open mode available flag
-     *
-     * @var array
-     */
-    protected $available_open_mode = ['r', 'r+', 'w', 'w+', 'x', 'x+', 'a', 'a+', 'c', 'c+'];
-
     /**
      * The constructor
      *
@@ -177,13 +170,6 @@ protected function fetchFile($path, $open_mode)
             return $path;
         }
         $open_mode = strtolower($open_mode);
-        if (! in_array($open_mode, $this->available_open_mode)) {
-            throw new InvalidArgumentException(
-                'Invalid `$open_mode` value. Available values are : "'
-                .implode('", "', $this->available_open_mode).'"'
-            );
-        }
-
         if ($path instanceof SplFileInfo) {
             return $path->openFile($open_mode);
         } elseif (is_string($path)) {
diff --git a/src/Reader.php b/src/Reader.php
index f837598c..8d82c031 100644
--- a/src/Reader.php
+++ b/src/Reader.php
@@ -51,11 +51,6 @@ class Reader extends AbstractCsv
      */
     use IteratorQuery;
 
-    /**
-     * {@inheritdoc}
-     */
-    protected $available_open_mode = ['r'];
-
     /**
      * Intelligent Array Combine
      *
diff --git a/src/Writer.php b/src/Writer.php
index d3e9ed05..c047953b 100644
--- a/src/Writer.php
+++ b/src/Writer.php
@@ -44,11 +44,6 @@
  */
 class Writer extends AbstractCsv
 {
-    /**
-     * {@inheritdoc}
-     */
-    protected $available_open_mode = ['r+', 'w', 'w+', 'x', 'x+', 'a', 'a+', 'c', 'c+'];
-
     /**
      * {@inheritdoc}
      */
diff --git a/test/WriterTest.php b/test/WriterTest.php
index ccd45cda..3b4a39db 100644
--- a/test/WriterTest.php
+++ b/test/WriterTest.php
@@ -22,14 +22,6 @@ public function setUp()
         $this->csv = new Writer(new SplTempFileObject);
     }
 
-    /**
-     * @expectedException InvalidArgumentException
-     */
-    public function testConstructorWithWrongOpenMode()
-    {
-        new Writer('foo.csv', 'r');
-    }
-
     public function testInsert()
     {
         $expected = [
diff --git a/test/foo.csv b/test/foo.csv
index 4307de42..0c85eae9 100644
--- a/test/foo.csv
+++ b/test/foo.csv
@@ -1,2 +1 @@
-1,2,3
 "john","doe","john.doe@example.com"
\ No newline at end of file