diff --git a/src/FontLib/BinaryStream.php b/src/FontLib/BinaryStream.php
index cc5e72c..3b1a53f 100644
--- a/src/FontLib/BinaryStream.php
+++ b/src/FontLib/BinaryStream.php
@@ -120,7 +120,7 @@ public static function getTempFile($allow_memory = true) {
    * @return bool True if the $offset position exists in the file
    */
   public function seek($offset) {
-    return fseek($this->f, $offset, SEEK_SET) == 0;
+    return fseek($this->f, (int)$offset, SEEK_SET) == 0;
   }
 
   /**