diff --git a/src/Plugin/migrate_plus/data_fetcher/File.php b/src/Plugin/migrate_plus/data_fetcher/File.php
index 33e3cae..ca85619 100644
--- a/src/Plugin/migrate_plus/data_fetcher/File.php
+++ b/src/Plugin/migrate_plus/data_fetcher/File.php
@@ -4,6 +4,7 @@ namespace Drupal\migrate_plus\Plugin\migrate_plus\data_fetcher;
 
 use Drupal\migrate\MigrateException;
 use Drupal\migrate_plus\DataFetcherPluginBase;
+use GuzzleHttp\Psr7\Response;
 
 /**
  * Retrieve data from a local path or general URL for migration.
@@ -34,19 +35,39 @@ class File extends DataFetcherPluginBase {
    * {@inheritdoc}
    */
   public function getResponse($url) {
-    $response = @file_get_contents($url);
-    if ($response === FALSE) {
+    // Try to start reading (only first 10 bytes) the file.
+    $content = $this->getFileContent($url, 0, 10);
+    if ($content === FALSE) {
       throw new MigrateException('file parser plugin: could not retrieve data from ' . $url);
     }
-    return $response;
+    return new Response(200, [], 'File is readable.');
   }
 
   /**
    * {@inheritdoc}
    */
   public function getResponseContent($url) {
-    $response = $this->getResponse($url);
-    return $response;
+    // Reads entire File into a string.
+    return $this->getFileContent($url);
+  }
+
+  /**
+   * Gets the content of a file by given $url (path).
+   *
+   * @param string $url
+   *   Name of the file to read.
+   * @param int $offset
+   *   The offset where the reading starts on the original stream.
+   *   Negative offsets count from the end of the stream.
+   * @param int|null $length
+   *   Maximum length of data read.
+   *   The default is to read until end of file is reached.
+   *
+   * @return string|false
+   *   Returns the content of the file or false on failure.
+   */
+  protected function getFileContent(string $url, int $offset = 0, int $length = NULL) {
+    return @file_get_contents($url, FALSE, NULL, $offset, $length);
   }
 
 }