diff --git a/.travis.yml b/.travis.yml
index dfc454e2f..e02a9e81e 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -9,7 +9,7 @@ branches:
 before_script:
  - mkdir plugins
  - wget -O plugins/DevTools.phar https://github.com/PocketMine/DevTools/releases/download/v1.9.0/DevTools_v1.9.0.phar
- - pecl install channel://pecl.php.net/pthreads-2.0.8
+ - pecl install channel://pecl.php.net/pthreads-2.0.9
  - pecl install channel://pecl.php.net/weakref-0.2.4
  - echo | pecl install channel://pecl.php.net/yaml-1.1.1
 
diff --git a/src/pocketmine/level/generator/noise/Simplex.php b/src/pocketmine/level/generator/noise/Simplex.php
index abcd6ce30..72c01f8cd 100644
--- a/src/pocketmine/level/generator/noise/Simplex.php
+++ b/src/pocketmine/level/generator/noise/Simplex.php
@@ -25,11 +25,10 @@ use pocketmine\utils\Random;
 
 /**
  * Generates simplex-based noise.
- * <p>
+ *
  * This is a modified version of the freely published version in the paper by
  * Stefan Gustavson at
- * <a href="http://staffwww.itn.liu.se/~stegu/simplexnoise/simplexnoise.pdf">
- * http://staffwww.itn.liu.se/~stegu/simplexnoise/simplexnoise.pdf</a>
+ * http://staffwww.itn.liu.se/~stegu/simplexnoise/simplexnoise.pdf
  */
 class Simplex extends Perlin{
 	protected static $SQRT_3;