diff --git a/src/ArrayWrapper.php b/src/ArrayWrapper.php
index 041aafa..044c68a 100644
--- a/src/ArrayWrapper.php
+++ b/src/ArrayWrapper.php
@@ -30,7 +30,7 @@ trait ArrayWrapper {
 	 * @param array $arr
 	 * @return ArrayType
 	 */
-	public function arr(array $arr)
+	public function arr(array $arr): ArrayType
 	{
 		return new ArrayType($arr);
 	}
diff --git a/src/Cache/Driver/SQLDriver.php b/src/Cache/Driver/SQLDriver.php
index dd31495..ccd32d1 100644
--- a/src/Cache/Driver/SQLDriver.php
+++ b/src/Cache/Driver/SQLDriver.php
@@ -19,6 +19,7 @@ namespace Aviat\Ion\Cache\Driver;
 use Aviat\Ion\ConfigInterface;
 use Aviat\Ion\Exception\ConfigException;
 use Aviat\Ion\Model\DB;
+use PDO;
 
 /**
  * Driver for caching via a traditional SQL database
@@ -63,8 +64,8 @@ class SQLDriver extends DB implements DriverInterface  {
 			->from('cache')
 			->where('key', $key)
 			->get();
-			
-		$row = $query->fetch(\PDO::FETCH_ASSOC);
+
+		$row = $query->fetch(PDO::FETCH_ASSOC);
 
 		if (empty($row))
 		{
@@ -106,7 +107,7 @@ class SQLDriver extends DB implements DriverInterface  {
 	{
 		$this->db->where('key', $key)
 			->delete('cache');
-			
+
 		return $this;
 	}
 
diff --git a/src/Config.php b/src/Config.php
index be541d5..045a3f0 100644
--- a/src/Config.php
+++ b/src/Config.php
@@ -16,9 +16,8 @@
 
 namespace Aviat\Ion;
 
-
 use Aviat\Ion\Exception\ConfigException;
-
+use Aviat\Ion\Type\ArrayType;
 use InvalidArgumentException;
 
 /**
@@ -31,18 +30,18 @@ class Config implements ConfigInterface {
 	/**
 	 * Config object
 	 *
-	 * @var \Aviat\Ion\Type\ArrayType
+	 * @var ArrayType
 	 */
 	protected $map = [];
 
 	/**
 	 * Constructor
 	 *
-	 * @param array $config_array
+	 * @param array $configArray
 	 */
-	public function __construct(array $config_array = [])
+	public function __construct(array $configArray = [])
 	{
-		$this->map = $this->arr($config_array);
+		$this->map = $this->arr($configArray);
 	}
 
 	/**
@@ -56,7 +55,7 @@ class Config implements ConfigInterface {
 	{
 		if (is_array($key))
 		{
-			return $this->map->get_deep_key($key);
+			return $this->map->getDeepKey($key);
 		}
 
 		return $this->map->get($key);
@@ -72,7 +71,7 @@ class Config implements ConfigInterface {
 	{
 		if (is_array($key))
 		{
-			$this->map->set_deep_key($key, NULL);
+			$this->map->setDeepKey($key, NULL);
 		}
 		else
 		{
@@ -87,13 +86,13 @@ class Config implements ConfigInterface {
 	 * @param integer|string|array $key
 	 * @param mixed                $value
 	 * @throws InvalidArgumentException
-	 * @return Config
+	 * @return ConfigInterface
 	 */
-	public function set($key, $value)
+	public function set($key, $value): ConfigInterface
 	{
 		if (is_array($key))
 		{
-			$this->map->set_deep_key($key, $value);
+			$this->map->setDeepKey($key, $value);
 		}
 		else if (is_scalar($key) && ! empty($key))
 		{
diff --git a/src/ConfigInterface.php b/src/ConfigInterface.php
index 80a431f..e5266e4 100644
--- a/src/ConfigInterface.php
+++ b/src/ConfigInterface.php
@@ -36,7 +36,7 @@ interface ConfigInterface {
 	 * @throws \InvalidArgumentException
 	 * @return ConfigInterface
 	 */
-	public function set($key, $value);
+	public function set($key, $value): ConfigInterface;
 
 	/**
 	 * Remove a config value
diff --git a/src/Di/Container.php b/src/Di/Container.php
index 10bdcaf..db10680 100644
--- a/src/Di/Container.php
+++ b/src/Di/Container.php
@@ -16,12 +16,9 @@
 
 namespace Aviat\Ion\Di;
 
+use Aviat\Ion\Di\Exception\{ContainerException, NotFoundException};
 use Psr\Log\LoggerInterface;
 
-use Aviat\Ion\Di\Exception\ContainerException;
-use Aviat\Ion\Di\Exception\NotFoundException;
-
-
 /**
  * Dependency container
  */
@@ -106,13 +103,13 @@ class Container implements ContainerInterface {
 	{
 		if ( ! is_string($id))
 		{
-			throw new ContainerException("Id must be a string");
+			throw new ContainerException('Id must be a string');
 		}
 
 		if ($this->has($id))
 		{
 			// By default, call a factory with the Container
-			$args = (is_array($args)) ? $args : [$this];
+			$args = is_array($args) ? $args : [$this];
 			$obj = call_user_func_array($this->container[$id], $args);
 
 			// Check for container interface, and apply the container to the object
@@ -130,7 +127,7 @@ class Container implements ContainerInterface {
 	 * @param Callable  $value - a factory callable for the item
 	 * @return ContainerInterface
 	 */
-	public function set($id, Callable $value)
+	public function set(string $id, Callable $value): ContainerInterface
 	{
 		$this->container[$id] = $value;
 		return $this;
@@ -144,7 +141,7 @@ class Container implements ContainerInterface {
 	 * @throws NotFoundException - No entry was found for this identifier.
 	 * @return ContainerInterface
 	 */
-	public function setInstance($id, $value)
+	public function setInstance(string $id, $value): ContainerInterface
 	{
 		if ( ! $this->has($id))
 		{
@@ -162,7 +159,7 @@ class Container implements ContainerInterface {
 	 * @param string $id Identifier of the entry to look for.
 	 * @return boolean
 	 */
-	public function has($id)
+	public function has($id): bool
 	{
 		return array_key_exists($id, $this->container);
 	}
@@ -173,7 +170,7 @@ class Container implements ContainerInterface {
 	 * @param  string $id The logger channel
 	 * @return boolean
 	 */
-	public function hasLogger($id = 'default')
+	public function hasLogger(string $id = 'default'): bool
 	{
 		return array_key_exists($id, $this->loggers);
 	}
@@ -185,7 +182,7 @@ class Container implements ContainerInterface {
 	 * @param string          $id     The logger 'channel'
 	 * @return ContainerInterface
 	 */
-	public function setLogger(LoggerInterface $logger, $id = 'default')
+	public function setLogger(LoggerInterface $logger, string $id = 'default'): ContainerInterface
 	{
 		$this->loggers[$id] = $logger;
 		return $this;
@@ -197,9 +194,9 @@ class Container implements ContainerInterface {
 	 * @param  string $id The logger to retrieve
 	 * @return LoggerInterface|null
 	 */
-	public function getLogger($id = 'default')
+	public function getLogger(string $id = 'default')
 	{
-		return ($this->hasLogger($id))
+		return $this->hasLogger($id)
 			? $this->loggers[$id]
 			: NULL;
 	}
@@ -217,8 +214,8 @@ class Container implements ContainerInterface {
 		$trait_name = __NAMESPACE__ . '\\ContainerAware';
 		$interface_name = __NAMESPACE__ . '\\ContainerAwareInterface';
 
-		$uses_trait = in_array($trait_name, class_uses($obj));
-		$implements_interface = in_array($interface_name, class_implements($obj));
+		$uses_trait = in_array($trait_name, class_uses($obj), TRUE);
+		$implements_interface = in_array($interface_name, class_implements($obj), TRUE);
 
 		if ($uses_trait OR $implements_interface)
 		{
diff --git a/src/Di/ContainerAware.php b/src/Di/ContainerAware.php
index 2c3ab20..19ddad1 100644
--- a/src/Di/ContainerAware.php
+++ b/src/Di/ContainerAware.php
@@ -45,7 +45,7 @@ trait ContainerAware {
 	 *
 	 * @return ContainerInterface
 	 */
-	public function getContainer()
+	public function getContainer(): ContainerInterface
 	{
 		return $this->container;
 	}
diff --git a/src/Di/ContainerAwareInterface.php b/src/Di/ContainerAwareInterface.php
index 6d41c5e..5a0ed87 100644
--- a/src/Di/ContainerAwareInterface.php
+++ b/src/Di/ContainerAwareInterface.php
@@ -34,7 +34,7 @@ interface ContainerAwareInterface {
 	 *
 	 * @return ContainerInterface
 	 */
-	public function getContainer();
+	public function getContainer(): ContainerInterface;
 
 }
 // End of ContainerAwareInterface.php
\ No newline at end of file
diff --git a/src/Di/ContainerInterface.php b/src/Di/ContainerInterface.php
index dfe053d..25ba642 100644
--- a/src/Di/ContainerInterface.php
+++ b/src/Di/ContainerInterface.php
@@ -16,13 +16,36 @@
 
 namespace Aviat\Ion\Di;
 
-use Interop\Container\ContainerInterface as InteropInterface;
 use Psr\Log\LoggerInterface;
 
 /**
  * Interface for the Dependency Injection Container
+ *
+ * Based on container-interop interface, but return types and
+ * scalar type hints make the interface incompatible to the PHP parser
+ *
+ * @see https://github.com/container-interop/container-interop
  */
-interface ContainerInterface extends InteropInterface {
+interface ContainerInterface {
+
+	/**
+	 * Finds an entry of the container by its identifier and returns it.
+	 *
+	 * @param string $id Identifier of the entry to look for.
+	 * @throws NotFoundException  No entry was found for this identifier.
+	 * @throws ContainerException Error while retrieving the entry.
+	 * @return mixed Entry.
+	 */
+	public function get($id);
+
+	/**
+	 * Returns true if the container can return an entry for the given identifier.
+	 * Returns false otherwise.
+	 *
+	 * @param string $id Identifier of the entry to look for.
+	 * @return boolean
+	 */
+	public function has($id): bool;
 
 	/**
 	 * Add a factory to the container
@@ -31,7 +54,7 @@ interface ContainerInterface extends InteropInterface {
 	 * @param Callable  $value - a factory callable for the item
 	 * @return ContainerInterface
 	 */
-	public function set($id, Callable $value);
+	public function set(string $id, Callable $value): ContainerInterface;
 
 	/**
 	 * Set a specific instance in the container for an existing factory
@@ -40,7 +63,7 @@ interface ContainerInterface extends InteropInterface {
 	 * @param mixed $value
 	 * @return ContainerInterface
 	 */
-	public function setInstance($id, $value);
+	public function setInstance(string $id, $value): ContainerInterface;
 
 	/**
 	 * Get a new instance of the specified item
@@ -55,22 +78,22 @@ interface ContainerInterface extends InteropInterface {
 	 * @param  string $id The logger channel
 	 * @return boolean
 	 */
-	public function hasLogger($id = 'default');
+	public function hasLogger(string $id = 'default'): bool;
 
 	/**
 	 * Add a logger to the Container
 	 *
 	 * @param LoggerInterface $logger
 	 * @param string          $id     The logger 'channel'
-	 * @return Container
+	 * @return ContainerInterface
 	 */
-	public function setLogger(LoggerInterface $logger, $id = 'default');
+	public function setLogger(LoggerInterface $logger, string $id = 'default'): ContainerInterface;
 
 	/**
 	 * Retrieve a logger for the selected channel
 	 *
-	 * @param  string $id The logger to retreive
+	 * @param  string $id The logger to retrieve
 	 * @return LoggerInterface|null
 	 */
-	public function getLogger($id = 'default');
+	public function getLogger(string $id = 'default');
 }
\ No newline at end of file
diff --git a/src/Di/Exception/ContainerException.php b/src/Di/Exception/ContainerException.php
index 9f1f6e1..b41fc75 100644
--- a/src/Di/Exception/ContainerException.php
+++ b/src/Di/Exception/ContainerException.php
@@ -16,10 +16,13 @@
 
 namespace Aviat\Ion\Di\Exception;
 
+use Exception;
+use Interop\Container\Exception\ContainerException as InteropContainerException;
+
 /**
  * Generic exception for Di Container
  */
-class ContainerException extends \Exception implements \Interop\Container\Exception\ContainerException {
+class ContainerException extends Exception implements InteropContainerException {
 
 }
 // End of ContainerException.php
\ No newline at end of file
diff --git a/src/Di/Exception/NotFoundException.php b/src/Di/Exception/NotFoundException.php
index 36e3400..acc6d4d 100644
--- a/src/Di/Exception/NotFoundException.php
+++ b/src/Di/Exception/NotFoundException.php
@@ -16,11 +16,13 @@
 
 namespace Aviat\Ion\Di\Exception;
 
+use Interop\Container\Exception\NotFoundException as InteropNotFoundException;
+
 /**
  * Exception for Di Container when trying to access a
  * key that doesn't exist in the container
  */
-class NotFoundException extends ContainerException implements \Interop\Container\Exception\NotFoundException {
+class NotFoundException extends ContainerException implements InteropNotFoundException {
 
 }
 // End of NotFoundException.php
\ No newline at end of file
diff --git a/src/Enum.php b/src/Enum.php
index 1faac79..e122010 100644
--- a/src/Enum.php
+++ b/src/Enum.php
@@ -33,7 +33,7 @@ abstract class Enum {
 	 *
 	 * @return array
 	 */
-	protected function getConstList()
+	protected function getConstList(): array
 	{
 		$reflect = new ReflectionClass($this);
 		return $reflect->getConstants();
@@ -44,7 +44,7 @@ abstract class Enum {
 	 * @param  mixed $key
 	 * @return boolean
 	 */
-	protected function isValid($key)
+	protected function isValid($key): bool
 	{
 		$values = array_values($this->getConstList());
 		return in_array($key, $values);
diff --git a/src/Exception/ConfigException.php b/src/Exception/ConfigException.php
index 68487ac..2e96d8c 100644
--- a/src/Exception/ConfigException.php
+++ b/src/Exception/ConfigException.php
@@ -16,9 +16,11 @@
 
 namespace Aviat\Ion\Exception;
 
+use InvalidArgumentException;
+
 /**
  * Exception for bad configuration
  */
-class ConfigException extends \InvalidArgumentException {
+class ConfigException extends InvalidArgumentException {
 
 }
\ No newline at end of file
diff --git a/src/Exception/DoubleRenderException.php b/src/Exception/DoubleRenderException.php
index 1bfd45b..d907114 100644
--- a/src/Exception/DoubleRenderException.php
+++ b/src/Exception/DoubleRenderException.php
@@ -16,10 +16,13 @@
 
 namespace Aviat\Ion\Exception;
 
+use Exception;
+use LogicException;
+
 /**
  * Exception called when a view is attempted to be sent twice
  */
-class DoubleRenderException extends \LogicException {
+class DoubleRenderException extends LogicException {
 
 	/**
 	 * DoubleRenderException constructor.
@@ -28,7 +31,7 @@ class DoubleRenderException extends \LogicException {
 	 * @param int    $code
 	 * @param null   $previous
 	 */
-	public function __construct($message = 'A view can only be rendered once, because headers can only be sent once.', $code = 0, $previous = NULL)
+	public function __construct(string $message = 'A view can only be rendered once, because headers can only be sent once.', int $code = 0, Exception $previous = NULL)
 	{
 		parent::__construct($message, $code, $previous);
 	}
diff --git a/src/Friend.php b/src/Friend.php
index a10f54c..5ff93f2 100644
--- a/src/Friend.php
+++ b/src/Friend.php
@@ -16,11 +16,11 @@
 
 namespace Aviat\Ion;
 
+use BadMethodCallException;
+use InvalidArgumentException;
 use ReflectionClass;
 use ReflectionMethod;
 use ReflectionProperty;
-use InvalidArgumentException;
-use BadMethodCallException;
 
 /**
  * Friend class for testing
@@ -62,7 +62,7 @@ class Friend {
 	 * @param  string $key
 	 * @return mixed
 	 */
-	public function __get($key)
+	public function __get(string $key)
 	{
 		if ($this->_reflect_->hasProperty($key))
 		{
@@ -80,7 +80,7 @@ class Friend {
 	 * @param mixed  $value
 	 * @return void
 	 */
-	public function __set($key, $value)
+	public function __set(string $key, $value)
 	{
 		if ($this->_reflect_->hasProperty($key))
 		{
@@ -97,7 +97,7 @@ class Friend {
 	 * @return mixed
 	 * @throws BadMethodCallException
 	 */
-	public function __call($method, $args)
+	public function __call(string $method, array $args)
 	{
 		if ( ! $this->_reflect_->hasMethod($method))
 		{
@@ -116,7 +116,7 @@ class Friend {
 	 * @param  string $name
 	 * @return ReflectionProperty|null
 	 */
-	private function _get_property($name)
+	private function _get_property(string $name)
 	{
 		try
 		{
diff --git a/src/Json.php b/src/Json.php
index 3b95f3e..7fee0cd 100644
--- a/src/Json.php
+++ b/src/Json.php
@@ -43,26 +43,26 @@ class Json {
 	 *
 	 * @param string $filename
 	 * @param mixed  $data
-	 * @param int    $json_options - Options to pass to json_encode
-	 * @param int    $file_options - Options to pass to file_get_contents
+	 * @param int    $jsonOptions - Options to pass to json_encode
+	 * @param int    $fileOptions - Options to pass to file_get_contents
 	 * @return int
 	 */
-	public static function encodeFile($filename, $data, $json_options = 0, $file_options = 0)
+	public static function encodeFile(string $filename, $data, int $jsonOptions = 0, int $fileOptions = 0): int
 	{
-		$json = self::encode($data, $json_options);
-		return file_put_contents($filename, $json, $file_options);
+		$json = self::encode($data, $jsonOptions);
+		return file_put_contents($filename, $json, $fileOptions);
 	}
 
 	/**
 	 * Decode data from json
 	 *
-	 * @param string $json
+	 * @param string|null $json
 	 * @param bool   $assoc
 	 * @param int    $depth
 	 * @param int    $options
 	 * @return mixed
 	 */
-	public static function decode($json, $assoc = TRUE, $depth = 512, $options = 0)
+	public static function decode($json, bool $assoc = TRUE, int $depth = 512, int $options = 0)
 	{
 		// Don't try to decode null
 		if (empty($json))
@@ -86,7 +86,7 @@ class Json {
  	 * @param int    $options
 	 * @return mixed
 	 */
-	public static function decodeFile($filename, $assoc = TRUE, $depth = 512, $options = 0)
+	public static function decodeFile(string $filename, bool $assoc = TRUE, int $depth = 512, int $options = 0)
 	{
 		$json = file_get_contents($filename);
 		return self::decode($json, $assoc, $depth, $options);
@@ -98,7 +98,7 @@ class Json {
 	 * @param  string $string
 	 * @return boolean
 	 */
-	public static function isJson($string)
+	public static function isJson(string $string): bool
 	{
 		return StringType::create($string)->isJson();
 	}
diff --git a/src/JsonException.php b/src/JsonException.php
index c4d9589..594c971 100644
--- a/src/JsonException.php
+++ b/src/JsonException.php
@@ -16,10 +16,12 @@
 
 namespace Aviat\Ion;
 
+use InvalidArgumentException;
+
 /**
  * Exceptions thrown by the Json class
  */
-class JsonException extends \InvalidArgumentException {
+class JsonException extends InvalidArgumentException {
 
 }
 // End of JsonException.php
\ No newline at end of file
diff --git a/src/StaticInstance.php b/src/StaticInstance.php
index 5848b0d..b5664ce 100644
--- a/src/StaticInstance.php
+++ b/src/StaticInstance.php
@@ -37,7 +37,7 @@ trait StaticInstance {
 	 * @param array  $args
 	 * @return mixed
 	 */
-	public function __call($method, $args)
+	public function __call(string $method, array $args)
 	{
 		if (method_exists($this, $method))
 		{
@@ -53,7 +53,7 @@ trait StaticInstance {
 	 * @param array  $args
 	 * @return mixed
 	 */
-	public static function __callStatic($method, $args)
+	public static function __callStatic(string $method, array $args)
 	{
 		$class = get_called_class();
 		if ( ! array_key_exists($class, self::$instance))
diff --git a/src/Transformer/AbstractTransformer.php b/src/Transformer/AbstractTransformer.php
index 70fdfac..c1ebc6f 100644
--- a/src/Transformer/AbstractTransformer.php
+++ b/src/Transformer/AbstractTransformer.php
@@ -16,12 +16,14 @@
 
 namespace Aviat\Ion\Transformer;
 
+use Aviat\Ion\StringWrapper;
+
 /**
  * Base class for data trasformation
  */
 abstract class AbstractTransformer implements TransformerInterface {
 
-	use \Aviat\Ion\StringWrapper;
+	use StringWrapper;
 
 	/**
 	 * Mutate the data structure
@@ -37,7 +39,7 @@ abstract class AbstractTransformer implements TransformerInterface {
 	 * @param  array|object $collection
 	 * @return array
 	 */
-	public function transform_collection($collection)
+	public function transformCollection($collection): array
 	{
 		$list = (array)$collection;
 		return array_map([$this, 'transform'], $list);
diff --git a/src/Type/ArrayType.php b/src/Type/ArrayType.php
index a5c6b36..5a972cb 100644
--- a/src/Type/ArrayType.php
+++ b/src/Type/ArrayType.php
@@ -16,6 +16,8 @@
 
 namespace Aviat\Ion\Type;
 
+use InvalidArgumentException;
+
 /**
  * Wrapper class for native array methods for convenience
  *
@@ -37,7 +39,7 @@ class ArrayType {
 	 *
 	 * @var array
 	 */
-	protected $native_methods = [
+	protected $nativeMethods = [
 		'chunk' => 'array_chunk',
 		'pluck' => 'array_column',
 		'key_diff' => 'array_diff_key',
@@ -62,7 +64,7 @@ class ArrayType {
 	 *
 	 * @var array
 	 */
-	protected $native_in_place_methods = [
+	protected $nativeInPlaceMethods = [
 		'shuffle' => 'shuffle',
 		'shift' => 'array_shift',
 		'unshift' => 'array_unshift',
@@ -88,35 +90,35 @@ class ArrayType {
 	 * @return mixed
 	 * @throws \InvalidArgumentException
 	 */
-	public function __call($method, $args)
+	public function __call(string $method, array $args)
 	{
 		// Simple mapping for the majority of methods
-		if (array_key_exists($method, $this->native_methods))
+		if (array_key_exists($method, $this->nativeMethods))
 		{
-			$func = $this->native_methods[$method];
+			$func = $this->nativeMethods[$method];
 			// Set the current array as the first argument of the method
 			array_unshift($args, $this->arr);
 			return call_user_func_array($func, $args);
 		}
 
 		// Mapping for in-place methods
-		if (array_key_exists($method, $this->native_in_place_methods))
+		if (array_key_exists($method, $this->nativeInPlaceMethods))
 		{
-			$func = $this->native_in_place_methods[$method];
+			$func = $this->nativeInPlaceMethods[$method];
 			$func($this->arr);
 			return $this->arr;
 		}
 
-		throw new \InvalidArgumentException("Method '{$method}' does not exist");
+		throw new InvalidArgumentException("Method '{$method}' does not exist");
 	}
 
 	/**
 	 * Does the passed key exist in the current array?
 	 *
-	 * @param string $key
+	 * @param int|string $key
 	 * @return bool
 	 */
-	public function has_key($key)
+	public function hasKey($key): bool
 	{
 		return array_key_exists($key, $this->arr);
 	}
@@ -129,7 +131,7 @@ class ArrayType {
 	 * @param mixed $value
 	 * @return array
 	 */
-	public function fill($start_index, $num, $value)
+	public function fill(int $start_index, int $num, $value): array
 	{
 		return array_fill($start_index, $num, $value);
 	}
@@ -140,7 +142,7 @@ class ArrayType {
 	 * @param callable $callback
 	 * @return array
 	 */
-	public function map(callable $callback)
+	public function map(callable $callback): array
 	{
 		return array_map($callback, $this->arr);
 	}
@@ -152,7 +154,7 @@ class ArrayType {
 	 * @param bool  $strict
 	 * @return false|integer|string
 	 */
-	public function search($value, $strict = FALSE)
+	public function search($value, bool $strict = TRUE)
 	{
 		return array_search($value, $this->arr, $strict);
 	}
@@ -164,7 +166,7 @@ class ArrayType {
 	 * @param bool  $strict
 	 * @return bool
 	 */
-	public function has($value, $strict = FALSE)
+	public function has($value, bool $strict = TRUE): bool
 	{
 		return in_array($value, $this->arr, $strict);
 	}
@@ -184,7 +186,7 @@ class ArrayType {
 		}
 		else
 		{
-			if ($this->has_key($key))
+			if ($this->hasKey($key))
 			{
 				$value =& $this->arr[$key];
 			}
@@ -200,7 +202,7 @@ class ArrayType {
 	 * @param mixed $value
 	 * @return ArrayType
 	 */
-	public function set($key, $value)
+	public function set($key, $value): ArrayType
 	{
 		$this->arr[$key] = $value;
 		return $this;
@@ -212,7 +214,7 @@ class ArrayType {
 	 * @param  array $key
 	 * @return mixed
 	 */
-	public function &get_deep_key(array $key)
+	public function &getDeepKey(array $key)
 	{
 		$pos =& $this->arr;
 
@@ -241,7 +243,7 @@ class ArrayType {
 	 * @param mixed $value
 	 * @return array
 	 */
-	public function set_deep_key(array $key, $value)
+	public function setDeepKey(array $key, $value): array
 	{
 		$pos =& $this->arr;
 
diff --git a/src/View.php b/src/View.php
index bd36537..faf3f70 100644
--- a/src/View.php
+++ b/src/View.php
@@ -75,7 +75,7 @@ abstract class View
 	 * @throws DoubleRenderException
 	 * @return string
 	 */
-	public function __toString()
+	public function __toString(): string
 	{
 		if ($this->hasRendered)
 		{
@@ -88,10 +88,10 @@ abstract class View
 	/**
 	 * Set the output string
 	 *
-	 * @param string $string
+	 * @param mixed $string
 	 * @return ViewInterface
 	 */
-	public function setOutput($string)
+	public function setOutput($string): ViewInterface
 	{
 		$this->response->getBody()->write($string);
 
@@ -104,7 +104,7 @@ abstract class View
 	 * @param string $string
 	 * @return ViewInterface
 	 */
-	public function appendOutput($string)
+	public function appendOutput(string $string): ViewInterface
 	{
 		return $this->setOutput($string);
 	}
@@ -115,7 +115,7 @@ abstract class View
 	 *
 	 * @return string
 	 */
-	public function getOutput()
+	public function getOutput(): string
 	{
 		return $this->response->getBody()->__toString();
 	}
diff --git a/src/View/HtmlView.php b/src/View/HtmlView.php
index a7281f0..c7d3f30 100644
--- a/src/View/HtmlView.php
+++ b/src/View/HtmlView.php
@@ -55,7 +55,7 @@ class HtmlView extends HttpView {
 	 * @param array  $data
 	 * @return string
 	 */
-	public function render_template($path, $data)
+	public function renderTemplate(string $path, array $data): string
 	{
 		$data['helper'] = $this->helper;
 		$data['escape'] = $this->helper->escape();
diff --git a/src/View/HttpView.php b/src/View/HttpView.php
index a5f843b..3bc1db5 100644
--- a/src/View/HttpView.php
+++ b/src/View/HttpView.php
@@ -41,7 +41,7 @@ class HttpView extends BaseView {
 	 * @param int    $code
 	 * @return void
 	 */
-	public function redirect($url, $code)
+	public function redirect(string $url, int $code)
 	{
 		ob_start();
 		$message = $this->response->getReasonPhrase($code);
@@ -64,7 +64,7 @@ class HttpView extends BaseView {
 	 * @param int $code
 	 * @return HttpView
 	 */
-	public function setStatusCode($code)
+	public function setStatusCode(int $code): HttpView
 	{
 		$this->response = $this->response->withStatus($code)
 			->withProtocolVersion('1.1');
diff --git a/src/View/JsonView.php b/src/View/JsonView.php
index eeb8e24..59dac5d 100644
--- a/src/View/JsonView.php
+++ b/src/View/JsonView.php
@@ -37,7 +37,7 @@ class JsonView extends HttpView {
 	 * @param mixed $string
 	 * @return ViewInterface
 	 */
-	public function setOutput($string)
+	public function setOutput($string): ViewInterface
 	{
 		if ( ! is_string($string))
 		{
diff --git a/src/ViewInterface.php b/src/ViewInterface.php
index 4213eee..a6f85cb 100644
--- a/src/ViewInterface.php
+++ b/src/ViewInterface.php
@@ -29,15 +29,15 @@ interface ViewInterface {
 	 * @throws DoubleRenderException
 	 * @return string
 	 */
-	public function __toString();
+	public function __toString(): string;
 
 	/**
 	 * Set the output string
 	 *
-	 * @param string $string
+	 * @param mixed $string
 	 * @return ViewInterface
 	 */
-	public function setOutput($string);
+	public function setOutput($string): ViewInterface;
 
 	/**
 	 * Append additional output.
@@ -45,7 +45,7 @@ interface ViewInterface {
 	 * @param string $string
 	 * @return ViewInterface
 	 */
-	public function appendOutput($string);
+	public function appendOutput(string $string): ViewInterface;
 
 	/**
 	 * Get the current output as a string. Does not
@@ -53,7 +53,7 @@ interface ViewInterface {
 	 *
 	 * @return string
 	 */
-	public function getOutput();
+	public function getOutput(): string;
 
 	/**
 	 * Send output to client. As it renders the view,
diff --git a/tests/Di/ContainerTest.php b/tests/Di/ContainerTest.php
index 7649aa7..a1f2a5d 100644
--- a/tests/Di/ContainerTest.php
+++ b/tests/Di/ContainerTest.php
@@ -16,7 +16,7 @@
 
 namespace Aviat\Ion\Tests\Di;
 
-use Aviat\Ion\Di\Container;
+use Aviat\Ion\Di\{Container, ContainerAware};
 use Aviat\Ion\Di\Exception\ContainerException;
 use Aviat\Ion\Tests\Ion_TestCase;
 use Monolog\Logger;
@@ -32,12 +32,11 @@ class FooTest {
 }
 
 class FooTest2 {
-	use \Aviat\Ion\Di\ContainerAware;
+	use ContainerAware;
 }
 
 class ContainerTest extends Ion_TestCase {
 
-
 	public function setUp()
 	{
 		$this->container = new Container();
@@ -85,15 +84,9 @@ class ContainerTest extends Ion_TestCase {
 	 */
 	public function testGetNewWithException($id, $exception, $message)
 	{
-		try
-		{
-			$this->container->getNew($id);
-		}
-		catch(ContainerException $e)
-		{
-			$this->assertInstanceOf($exception, $e);
-			$this->assertEquals($message, $e->getMessage());
-		}
+		$this->expectException($exception);
+		$this->expectExceptionMessage($message);
+		$this->container->getNew($id);
 	}
 
 	public function dataSetInstanceWithException()
diff --git a/tests/Transformer/AbstractTransformerTest.php b/tests/Transformer/AbstractTransformerTest.php
index 9988c44..cab68ba 100644
--- a/tests/Transformer/AbstractTransformerTest.php
+++ b/tests/Transformer/AbstractTransformerTest.php
@@ -102,7 +102,7 @@ class AbstractTransformerTest extends Ion_TestCase {
 	 */
 	public function testTransformCollection($original, $expected)
 	{
-		$actual = $this->transformer->transform_collection($original);
+		$actual = $this->transformer->transformCollection($original);
 		$this->assertEquals($expected, $actual);
 	}
 }
\ No newline at end of file
diff --git a/tests/Type/ArrayTypeTest.php b/tests/Type/ArrayTypeTest.php
index 4acad36..489f810 100644
--- a/tests/Type/ArrayTypeTest.php
+++ b/tests/Type/ArrayTypeTest.php
@@ -124,8 +124,8 @@ class ArrayTypeTest extends Ion_TestCase {
 			]
 		];
 		$obj = $this->arr($arr);
-		$this->assertEquals('foobar', $obj->get_deep_key(['baz', 'bar']));
-		$this->assertNull($obj->get_deep_key(['foo', 'bar', 'baz']));
+		$this->assertEquals('foobar', $obj->getDeepKey(['baz', 'bar']));
+		$this->assertNull($obj->getDeepKey(['foo', 'bar', 'baz']));
 	}
 
 	public function testMap()
@@ -165,8 +165,8 @@ class ArrayTypeTest extends Ion_TestCase {
 			'a' => 'b',
 			'z' => 'y'
 		]);
-		$this->assertTrue($obj->has_key('a'));
-		$this->assertFalse($obj->has_key('b'));
+		$this->assertTrue($obj->hasKey('a'));
+		$this->assertFalse($obj->hasKey('b'));
 	}
 
 	public function testHas()
diff --git a/tests/View/HtmlViewTest.php b/tests/View/HtmlViewTest.php
index 5e355dd..d62f79b 100644
--- a/tests/View/HtmlViewTest.php
+++ b/tests/View/HtmlViewTest.php
@@ -34,7 +34,7 @@ class HtmlViewTest extends HttpViewTest {
 	{
 		$path = _dir(self::TEST_VIEW_DIR, 'test_view.php');
 		$expected = '<tag>foo</tag>';
-		$actual = $this->view->render_template($path, [
+		$actual = $this->view->renderTemplate($path, [
 			'var' => 'foo'
 		]);
 		$this->assertEquals($expected, $actual);