diff --git a/src/pocketmine/command/defaults/TeleportCommand.php b/src/pocketmine/command/defaults/TeleportCommand.php
index b83b21677..899086540 100644
--- a/src/pocketmine/command/defaults/TeleportCommand.php
+++ b/src/pocketmine/command/defaults/TeleportCommand.php
@@ -49,7 +49,7 @@ class TeleportCommand extends VanillaCommand{
 		}
 
 		$args = array_values(array_filter($args, function($arg){
-			return strlen($arg) > 0;
+			return $arg !== "";
 		}));
 		if(count($args) < 1 or count($args) > 6){
 			throw new InvalidCommandSyntaxException();
diff --git a/src/pocketmine/level/format/io/leveldb/LevelDB.php b/src/pocketmine/level/format/io/leveldb/LevelDB.php
index 5b94d0f4c..725c572ff 100644
--- a/src/pocketmine/level/format/io/leveldb/LevelDB.php
+++ b/src/pocketmine/level/format/io/leveldb/LevelDB.php
@@ -377,7 +377,7 @@ class LevelDB extends BaseLevelProvider{
 
 		/** @var CompoundTag[] $entities */
 		$entities = [];
-		if(($entityData = $this->db->get($index . self::TAG_ENTITY)) !== false and strlen($entityData) > 0){
+		if(($entityData = $this->db->get($index . self::TAG_ENTITY)) !== false and $entityData !== ""){
 			$entities = $nbt->read($entityData, true);
 			if(!is_array($entities)){
 				$entities = [$entities];
@@ -392,7 +392,7 @@ class LevelDB extends BaseLevelProvider{
 		}
 
 		$tiles = [];
-		if(($tileData = $this->db->get($index . self::TAG_BLOCK_ENTITY)) !== false and strlen($tileData) > 0){
+		if(($tileData = $this->db->get($index . self::TAG_BLOCK_ENTITY)) !== false and $tileData !== ""){
 			$tiles = $nbt->read($tileData, true);
 			if(!is_array($tiles)){
 				$tiles = [$tiles];
@@ -402,7 +402,7 @@ class LevelDB extends BaseLevelProvider{
 		//TODO: extra data should be converted into blockstorage layers (first they need to be implemented!)
 		/*
 		$extraData = [];
-		if(($extraRawData = $this->db->get($index . self::TAG_BLOCK_EXTRA_DATA)) !== false and strlen($extraRawData) > 0){
+		if(($extraRawData = $this->db->get($index . self::TAG_BLOCK_EXTRA_DATA)) !== false and $extraRawData !== ""){
 			$binaryStream->setBuffer($extraRawData, 0);
 			$count = $binaryStream->getLInt();
 			for($i = 0; $i < $count; ++$i){
diff --git a/src/pocketmine/network/rcon/RCONInstance.php b/src/pocketmine/network/rcon/RCONInstance.php
index d1e98da2e..0ea1d771b 100644
--- a/src/pocketmine/network/rcon/RCONInstance.php
+++ b/src/pocketmine/network/rcon/RCONInstance.php
@@ -177,7 +177,7 @@ class RCONInstance extends Thread{
 									$disconnect[$id] = $sock;
 									break;
 								}
-								if(strlen($payload) > 0){
+								if($payload !== ""){
 									$this->cmd = ltrim($payload);
 									$this->synchronized(function(){
 										$this->notifier->wakeupSleeper();
diff --git a/src/pocketmine/permission/BanEntry.php b/src/pocketmine/permission/BanEntry.php
index 790fb8ada..3c91d5839 100644
--- a/src/pocketmine/permission/BanEntry.php
+++ b/src/pocketmine/permission/BanEntry.php
@@ -168,7 +168,7 @@ class BanEntry{
 				}
 
 				$expire = trim(array_shift($str));
-				if(strtolower($expire) !== "forever" and strlen($expire) > 0){
+				if($expire !== "" and strtolower($expire) !== "forever"){
 					$entry->setExpires(self::parseDate($expire));
 				}
 				if(empty($str)){