diff --git a/CHANGELOG.md b/CHANGELOG.md
index ca306b1..1b4abb7 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -18,6 +18,12 @@ Security - in case of vulnerabilities.
 
 _TBD_
 
+## [1.0.1] 2018-12-27
+
+### Changed
+
+- Enable strict type mode for all classes (#7)
+
 ## [1.0.0] 2018-12-23
 
 Initial release.
diff --git a/src/BadFunctionCallException.php b/src/BadFunctionCallException.php
index d440166..14af025 100644
--- a/src/BadFunctionCallException.php
+++ b/src/BadFunctionCallException.php
@@ -3,6 +3,8 @@
  * {@see https://github.com/zee/ Zee Project (c)}
  */
 
+declare(strict_types=1);
+
 namespace Zee\Exceptions;
 
 class BadFunctionCallException extends \BadFunctionCallException implements InformativeException
diff --git a/src/BadMethodCallException.php b/src/BadMethodCallException.php
index ea1bc93..35c1ad1 100644
--- a/src/BadMethodCallException.php
+++ b/src/BadMethodCallException.php
@@ -3,6 +3,8 @@
  * {@see https://github.com/zee/ Zee Project (c)}
  */
 
+declare(strict_types=1);
+
 namespace Zee\Exceptions;
 
 class BadMethodCallException extends \BadMethodCallException implements InformativeException
diff --git a/src/DomainException.php b/src/DomainException.php
index 3d42328..3c51706 100644
--- a/src/DomainException.php
+++ b/src/DomainException.php
@@ -3,6 +3,8 @@
  * {@see https://github.com/zee/ Zee Project (c)}
  */
 
+declare(strict_types=1);
+
 namespace Zee\Exceptions;
 
 class DomainException extends \DomainException implements InformativeException
diff --git a/src/InformativeException.php b/src/InformativeException.php
index 7ae9d3c..37da73c 100644
--- a/src/InformativeException.php
+++ b/src/InformativeException.php
@@ -3,6 +3,8 @@
  * {@see https://github.com/zee/ Zee Project (c)}
  */
 
+declare(strict_types=1);
+
 namespace Zee\Exceptions;
 
 /**
diff --git a/src/InvalidArgumentException.php b/src/InvalidArgumentException.php
index 7512dd5..880738a 100644
--- a/src/InvalidArgumentException.php
+++ b/src/InvalidArgumentException.php
@@ -3,6 +3,8 @@
  * {@see https://github.com/zee/ Zee Project (c)}
  */
 
+declare(strict_types=1);
+
 namespace Zee\Exceptions;
 
 class InvalidArgumentException extends \InvalidArgumentException implements InformativeException
diff --git a/src/LengthException.php b/src/LengthException.php
index 47dc88a..086eed6 100644
--- a/src/LengthException.php
+++ b/src/LengthException.php
@@ -3,6 +3,8 @@
  * {@see https://github.com/zee/ Zee Project (c)}
  */
 
+declare(strict_types=1);
+
 namespace Zee\Exceptions;
 
 class LengthException extends \LengthException implements InformativeException
diff --git a/src/LogicException.php b/src/LogicException.php
index a3fdb8b..1a11f0d 100644
--- a/src/LogicException.php
+++ b/src/LogicException.php
@@ -3,6 +3,8 @@
  * {@see https://github.com/zee/ Zee Project (c)}
  */
 
+declare(strict_types=1);
+
 namespace Zee\Exceptions;
 
 class LogicException extends \LogicException implements InformativeException
diff --git a/src/OutOfBoundsException.php b/src/OutOfBoundsException.php
index 1bb3758..45c6463 100644
--- a/src/OutOfBoundsException.php
+++ b/src/OutOfBoundsException.php
@@ -3,6 +3,8 @@
  * {@see https://github.com/zee/ Zee Project (c)}
  */
 
+declare(strict_types=1);
+
 namespace Zee\Exceptions;
 
 class OutOfBoundsException extends \OutOfBoundsException implements InformativeException
diff --git a/src/OutOfRangeException.php b/src/OutOfRangeException.php
index 32a0d62..7405ec6 100644
--- a/src/OutOfRangeException.php
+++ b/src/OutOfRangeException.php
@@ -3,6 +3,8 @@
  * {@see https://github.com/zee/ Zee Project (c)}
  */
 
+declare(strict_types=1);
+
 namespace Zee\Exceptions;
 
 class OutOfRangeException extends \OutOfRangeException implements InformativeException
diff --git a/src/OverflowException.php b/src/OverflowException.php
index dc4814b..24ee068 100644
--- a/src/OverflowException.php
+++ b/src/OverflowException.php
@@ -3,6 +3,8 @@
  * {@see https://github.com/zee/ Zee Project (c)}
  */
 
+declare(strict_types=1);
+
 namespace Zee\Exceptions;
 
 class OverflowException extends \OverflowException implements InformativeException
diff --git a/src/RangeException.php b/src/RangeException.php
index 7021340..4541a45 100644
--- a/src/RangeException.php
+++ b/src/RangeException.php
@@ -3,6 +3,8 @@
  * {@see https://github.com/zee/ Zee Project (c)}
  */
 
+declare(strict_types=1);
+
 namespace Zee\Exceptions;
 
 class RangeException extends \RangeException implements InformativeException
diff --git a/src/RuntimeException.php b/src/RuntimeException.php
index 5958e79..a4958de 100644
--- a/src/RuntimeException.php
+++ b/src/RuntimeException.php
@@ -3,6 +3,8 @@
  * {@see https://github.com/zee/ Zee Project (c)}
  */
 
+declare(strict_types=1);
+
 namespace Zee\Exceptions;
 
 class RuntimeException extends \RuntimeException implements InformativeException
diff --git a/src/ThrowableContextTrait.php b/src/ThrowableContextTrait.php
index 6efcbd1..8f35776 100644
--- a/src/ThrowableContextTrait.php
+++ b/src/ThrowableContextTrait.php
@@ -3,6 +3,8 @@
  * {@see https://github.com/zee/ Zee Project (c)}
  */
 
+declare(strict_types=1);
+
 namespace Zee\Exceptions;
 
 trait ThrowableContextTrait
diff --git a/src/UnderflowException.php b/src/UnderflowException.php
index 8b45c9b..b1edc5c 100644
--- a/src/UnderflowException.php
+++ b/src/UnderflowException.php
@@ -3,6 +3,8 @@
  * {@see https://github.com/zee/ Zee Project (c)}
  */
 
+declare(strict_types=1);
+
 namespace Zee\Exceptions;
 
 class UnderflowException extends \UnderflowException implements InformativeException
diff --git a/src/UnexpectedValueException.php b/src/UnexpectedValueException.php
index 46da70f..170b83a 100644
--- a/src/UnexpectedValueException.php
+++ b/src/UnexpectedValueException.php
@@ -3,6 +3,8 @@
  * {@see https://github.com/zee/ Zee Project (c)}
  */
 
+declare(strict_types=1);
+
 namespace Zee\Exceptions;
 
 class UnexpectedValueException extends \UnexpectedValueException implements InformativeException
diff --git a/tests/ReadExceptionContextTest.php b/tests/ReadExceptionContextTest.php
index 2fbfafa..68f6606 100644
--- a/tests/ReadExceptionContextTest.php
+++ b/tests/ReadExceptionContextTest.php
@@ -3,6 +3,8 @@
  * {@see https://github.com/zee/ Zee Project (c)}
  */
 
+declare(strict_types=1);
+
 namespace Zee\Exceptions\Tests;
 
 use PHPUnit\Framework\TestCase;