diff --git a/changelogs/3.9.md b/changelogs/3.9.md
index 57c82b7cd..3da77cc31 100644
--- a/changelogs/3.9.md
+++ b/changelogs/3.9.md
@@ -104,4 +104,26 @@ Plugin developers should **only** update their required API to this version if y
 # 3.9.7
 - Fixed a crash that could occur during timezone detection.
 - Squid no longer spin around constantly in enclosed spaces. Their performance impact is reduced.
-- Cleaned up the bootstrap file.
\ No newline at end of file
+- Cleaned up the bootstrap file.
+
+# 3.9.8
+- Added [PHPStan](https://github.com/phpstan/phpstan) configuration. PHPStan is now used on CI for automated QA, which should improve stability and quality going forward.
+- The following constants are now autoloaded when loading the Composer autoloader:
+  - `pocketmine\NAME`
+  - `pocketmine\BASE_VERSION`
+  - `pocketmine\IS_DEVELOPMENT_BUILD`
+  - `pocketmine\BUILD_NUMBER`
+  - `INT32_MIN`
+  - `INT32_MAX`
+  - `INT32_MASK`
+- Fixed memory leaks and crashes caused by plugin use of `Player->showPlayer()` and `Entity->spawnTo()`.
+- Fixed crashes that could occur when tile classes were overridden with classes incompatible with the originals.
+- Fixed improper handling of non-Compound root NBT tags on network itemstack decoding.
+- Fixed paintings dropping multiple items when destroyed by block updates.
+- Fixed `var_dump()` not showing private and protected properties of `DataPacket` subclasses.
+- Fixed overloads with zero arguments being missing when decoding `AvailableCommandsPacket`.
+- `CraftingDataPacket` now retains the `cleanRecipes` field when decoding.
+- Fixed `Block->getMetadata()` returning null (non-iterable).
+- `PlayerChatEvent` documentation has been updated to specify that `CommandSender` recipients are accepted. This behaviour was already present in previous versions, but incorrectly documented.
+- Fixed various issues with PHPDoc comments reported by PHPStan.
+- Fixed various minor code nits reported by PHPStan.
diff --git a/src/GlobalConstants.php b/src/GlobalConstants.php
index a9550cc43..d3b4a9f9a 100644
--- a/src/GlobalConstants.php
+++ b/src/GlobalConstants.php
@@ -27,4 +27,4 @@ define('pocketmine\_GLOBAL_CONSTANTS_INCLUDED', true);
 
 const INT32_MIN = -0x80000000;
 const INT32_MAX = 0x7fffffff;
-define("INT32_MASK", is_int(0xffffffff) ? 0xffffffff : -1);
+const INT32_MASK = 0xffffffff;
diff --git a/src/network/upnp/UPnP.php b/src/network/upnp/UPnP.php
index 56702f882..6862df185 100644
--- a/src/network/upnp/UPnP.php
+++ b/src/network/upnp/UPnP.php
@@ -63,8 +63,7 @@ class UPnP implements NetworkInterface{
 		/** @noinspection PhpUndefinedClassInspection */
 		$com = new \COM("HNetCfg.NATUPnP");
 		/** @noinspection PhpUndefinedFieldInspection */
-
-		if($com === false or !is_object($com->StaticPortMappingCollection)){
+		if(!is_object($com->StaticPortMappingCollection)){
 			throw new \RuntimeException("UPnP unsupported or network discovery is not enabled");
 		}
 		/** @noinspection PhpUndefinedFieldInspection */