diff --git a/tests/CLImateTest.php b/tests/CLImateTest.php
index 29ed0f92..c26ca190 100644
--- a/tests/CLImateTest.php
+++ b/tests/CLImateTest.php
@@ -4,8 +4,11 @@
 
 use League\CLImate\Exceptions\InvalidArgumentException;
 use League\CLImate\Exceptions\UnexpectedValueException;
+use League\CLImate\Tests\CustomObject\Basic;
 use League\CLImate\Tests\CustomObject\BasicObject;
 use League\CLImate\Tests\CustomObject\BasicObjectArgument;
+use League\CLImate\Tests\CustomObject\Dummy;
+use League\CLImate\Tests\CustomObject\Dynamic;
 
 class CLImateTest extends TestBase
 {
@@ -57,7 +60,7 @@ public function it_can_be_extended_using_a_basic_object_as_string()
         $this->shouldWrite("\e[mBy Custom Object: This is something my custom object is handling.\e[0m");
         $this->shouldHavePersisted();
 
-        $this->cli->extend('League\CLImate\Tests\CustomObject\Basic');
+        $this->cli->extend(Basic::class);
         $this->cli->basic('This is something my custom object is handling.');
     }
 
@@ -90,16 +93,16 @@ public function it_can_be_extended_using_a_basic_object_with_argument_setter()
     /** @test */
     public function it_can_be_extended_using_a_dynamic_object()
     {
-        $this->cli->extend('League\CLImate\Tests\CustomObject\Dynamic');
+        $this->cli->extend(Dynamic::class);
         $obj = $this->cli->dynamic();
 
-        $this->assertInstanceOf('League\CLImate\Tests\CustomObject\Dynamic', $obj);
+        $this->assertInstanceOf(Dynamic::class, $obj);
     }
 
     /** @test */
     public function it_will_yell_if_extending_and_class_doesnt_exist()
     {
-        $class = 'League\CLImate\Tests\CustomObject\NowhereToBeFound';
+        $class = "NoSuchClass";
         $this->expectException(UnexpectedValueException::class);
         $this->expectExceptionMessage("Class does not exist: {$class}");
         $this->cli->extend($class);
@@ -108,7 +111,7 @@ public function it_will_yell_if_extending_and_class_doesnt_exist()
     /** @test */
     public function it_will_yell_if_it_doesnt_implement_proper_interfaces()
     {
-        $class = 'League\CLImate\Tests\CustomObject\Dummy';
+        $class = Dummy::class;
         $this->expectException(InvalidArgumentException::class);
         $this->expectExceptionMessage("Class must implement either");
         $this->cli->extend($class);
@@ -123,7 +126,7 @@ public function it_will_accept_a_custom_key_for_an_extension()
         $this->shouldWrite("\e[mBy Custom Object: This is something my custom object is handling.\e[0m");
         $this->shouldHavePersisted();
 
-        $this->cli->extend('League\CLImate\Tests\CustomObject\Basic', 'myCustomMethod');
+        $this->cli->extend(Basic::class, 'myCustomMethod');
         $this->cli->myCustomMethod('This is something my custom object is handling.');
     }
 
@@ -134,8 +137,8 @@ public function it_will_accept_an_array_of_extensions()
         $this->shouldHavePersisted();
 
         $extensions = [
-            'League\CLImate\Tests\CustomObject\Basic',
-            'League\CLImate\Tests\CustomObject\Dynamic',
+            Basic::class,
+            Dynamic::class,
         ];
 
         $this->cli->extend($extensions);
@@ -144,7 +147,7 @@ public function it_will_accept_an_array_of_extensions()
 
         $obj = $this->cli->dynamic();
 
-        $this->assertInstanceOf('League\CLImate\Tests\CustomObject\Dynamic', $obj);
+        $this->assertInstanceOf(Dynamic::class, $obj);
     }
 
     /** @test */
@@ -154,8 +157,8 @@ public function it_will_accept_an_array_of_extensions_with_custom_keys()
         $this->shouldHavePersisted();
 
         $extensions = [
-            'whatever'  => 'League\CLImate\Tests\CustomObject\Basic',
-            'something' => 'League\CLImate\Tests\CustomObject\Dynamic',
+            'whatever'  => Basic::class,
+            'something' => Dynamic::class,
         ];
 
         $this->cli->extend($extensions);
@@ -164,6 +167,6 @@ public function it_will_accept_an_array_of_extensions_with_custom_keys()
 
         $obj = $this->cli->something();
 
-        $this->assertInstanceOf('League\CLImate\Tests\CustomObject\Dynamic', $obj);
+        $this->assertInstanceOf(Dynamic::class, $obj);
     }
 }
diff --git a/tests/Decorator/Parser/AnsiTest.php b/tests/Decorator/Parser/AnsiTest.php
index b4350e22..b849ab0b 100644
--- a/tests/Decorator/Parser/AnsiTest.php
+++ b/tests/Decorator/Parser/AnsiTest.php
@@ -7,7 +7,7 @@
 use League\CLImate\Decorator\Parser\ParserFactory;
 use League\CLImate\Decorator\Style;
 use League\CLImate\Decorator\Tags;
-use League\CLImate\TerminalObject;
+use League\CLImate\TerminalObject\Basic\BasicTerminalObject;
 use League\CLImate\TerminalObject\Router\BasicRouter;
 use League\CLImate\Tests\TestBase;
 use League\CLImate\Util\System\Linux;
@@ -28,7 +28,8 @@ public function it_can_output_with_ansi()
 
         $style  = new Style();
         $parser = new Ansi($style->current(), new Tags($style->all()));
-        $obj = Mockery::mock('League\CLImate\TerminalObject');
+
+        $obj = Mockery::mock(BasicTerminalObject::class);
         $obj->shouldReceive('result')->once()->andReturn("<green>I am green</green>");
         $obj->shouldReceive('sameLine')->once()->andReturn(false);
         $obj->shouldReceive('getParser')->once()->andReturn($parser);
@@ -52,7 +53,7 @@ public function it_can_output_without_ansi()
         $style  = new Style();
         $parser = new NonAnsi($style->current(), new Tags($style->all()));
 
-        $obj = Mockery::mock('League\CLImate\TerminalObject');
+        $obj = Mockery::mock(BasicTerminalObject::class);
         $obj->shouldReceive('result')->once()->andReturn("<green>I am not green</green>");
         $obj->shouldReceive('sameLine')->once()->andReturn(false);
         $obj->shouldReceive('getParser')->once()->andReturn($parser);
@@ -67,12 +68,12 @@ public function it_can_output_without_ansi()
     /** @test */
     public function it_will_recognize_non_ansi_systems()
     {
-        $system = Mockery::mock('League\CLImate\Util\System\Windows');
+        $system = Mockery::mock(Windows::class);
         $system->shouldReceive('hasAnsiSupport')->andReturn(false);
 
         $parser = ParserFactory::getInstance($system, [], new Tags([]));
 
-        $this->assertInstanceOf('League\CLImate\Decorator\Parser\NonAnsi', $parser);
+        $this->assertInstanceOf(NonAnsi::class, $parser);
     }
 
     /**
diff --git a/tests/TerminalObject/Dynamic/Animation/AnimationTest.php b/tests/TerminalObject/Dynamic/Animation/AnimationTest.php
index 2806cb6b..4f16d07a 100644
--- a/tests/TerminalObject/Dynamic/Animation/AnimationTest.php
+++ b/tests/TerminalObject/Dynamic/Animation/AnimationTest.php
@@ -2,6 +2,7 @@
 
 namespace League\CLImate\Tests\TerminalObject\Dynamic;
 
+use League\CLImate\TerminalObject\Helper\Sleeper;
 use League\CLImate\Tests\TestBase;
 use Mockery;
 
@@ -37,7 +38,7 @@ protected function blankLines($count = 1)
 
     protected function getSleeper($count)
     {
-        $sleeper = Mockery::mock('League\CLImate\TerminalObject\Helper\Sleeper');
+        $sleeper = Mockery::mock(Sleeper::class);
         $sleeper->shouldReceive('sleep')->times($count);
 
         return $sleeper;
diff --git a/tests/TestBase.php b/tests/TestBase.php
index d67b9f84..118138b8 100644
--- a/tests/TestBase.php
+++ b/tests/TestBase.php
@@ -3,6 +3,9 @@
 namespace League\CLImate\Tests;
 
 use League\CLImate\CLImate;
+use League\CLImate\Util\Output;
+use League\CLImate\Util\Reader\Stdin;
+use League\CLImate\Util\System\Linux;
 use Mockery;
 use PHPUnit\Framework\TestCase;
 
@@ -28,13 +31,13 @@ public function setUp(): void
     {
         self::$functions = Mockery::mock();
 
-        $system = Mockery::mock('League\CLImate\Util\System\Linux');
+        $system = Mockery::mock(Linux::class);
         $system->shouldReceive('hasAnsiSupport')->andReturn(true);
         $system->shouldReceive('width')->andReturn(80);
 
         $this->util   = new \League\CLImate\Util\UtilFactory($system);
-        $this->output = Mockery::mock('League\CLImate\Util\Output');
-        $this->reader = Mockery::mock('League\CLImate\Util\Reader\Stdin');
+        $this->output = Mockery::mock(Output::class);
+        $this->reader = Mockery::mock(Stdin::class);
 
         $this->cli = new CLImate();
         $this->cli->setOutput($this->output);
diff --git a/tests/Util/OutputTest.php b/tests/Util/OutputTest.php
index e3da9cf2..148703b5 100644
--- a/tests/Util/OutputTest.php
+++ b/tests/Util/OutputTest.php
@@ -5,6 +5,9 @@
 use League\CLImate\Exceptions\InvalidArgumentException;
 use League\CLImate\Tests\TestBase;
 use League\CLImate\Util\Output;
+use League\CLImate\Util\Writer\Buffer;
+use League\CLImate\Util\Writer\StdErr;
+use League\CLImate\Util\Writer\StdOut;
 use Mockery;
 
 use function get_class;
@@ -17,7 +20,7 @@ class OutputTest extends TestBase
      */
     public function it_can_output_content()
     {
-        $out = Mockery::mock('League\CLImate\Util\Writer\StdOut');
+        $out = Mockery::mock(StdOut::class);
         $out->shouldReceive('write')->once()->with("Oh, hey there." . \PHP_EOL);
 
         $output = new Output();
@@ -33,7 +36,7 @@ public function it_can_output_content()
      */
     public function it_can_output_content_without_a_new_line()
     {
-        $out = Mockery::mock('League\CLImate\Util\Writer\StdOut');
+        $out = Mockery::mock(StdOut::class);
         $out->shouldReceive('write')->once()->with("Oh, hey there.");
 
         $output = new Output();
@@ -49,7 +52,7 @@ public function it_can_output_content_without_a_new_line()
      */
     public function it_can_default_to_a_writer()
     {
-        $error = Mockery::mock('League\CLImate\Util\Writer\StdErr');
+        $error = Mockery::mock(StdErr::class);
         $error->shouldReceive('write')->once()->with("Oh, hey there.");
 
         $output = new Output();
@@ -66,10 +69,10 @@ public function it_can_default_to_a_writer()
      */
     public function it_can_default_to_multiple_writers()
     {
-        $out = Mockery::mock('League\CLImate\Util\Writer\StdOut');
+        $out = Mockery::mock(StdOut::class);
         $out->shouldReceive('write')->once()->with("Oh, hey there.");
 
-        $error = Mockery::mock('League\CLImate\Util\Writer\StdErr');
+        $error = Mockery::mock(StdErr::class);
         $error->shouldReceive('write')->once()->with("Oh, hey there.");
 
         $output = new Output();
@@ -87,10 +90,10 @@ public function it_can_default_to_multiple_writers()
      */
     public function it_can_add_a_default()
     {
-        $out = Mockery::mock('League\CLImate\Util\Writer\StdOut');
+        $out = Mockery::mock(StdOut::class);
         $out->shouldReceive('write')->once()->with("Oh, hey there.");
 
-        $error = Mockery::mock('League\CLImate\Util\Writer\StdErr');
+        $error = Mockery::mock(StdErr::class);
         $error->shouldReceive('write')->once()->with("Oh, hey there.");
 
         $output = new Output();
@@ -109,10 +112,10 @@ public function it_can_add_a_default()
      */
     public function it_can_handle_multiple_writers_for_one_key()
     {
-        $out = Mockery::mock('League\CLImate\Util\Writer\StdOut');
+        $out = Mockery::mock(StdOut::class);
         $out->shouldReceive('write')->once()->with('Oh, hey there.');
 
-        $error = Mockery::mock('League\CLImate\Util\Writer\StdErr');
+        $error = Mockery::mock(StdErr::class);
         $error->shouldReceive('write')->once()->with('Oh, hey there.');
 
         $output = new Output();
@@ -129,10 +132,10 @@ public function it_can_handle_multiple_writers_for_one_key()
      */
     public function it_can_take_existing_writer_keys_and_resolve_them()
     {
-        $out = Mockery::mock('League\CLImate\Util\Writer\StdOut');
+        $out = Mockery::mock(StdOut::class);
         $out->shouldReceive('write')->once()->with('Oh, hey there.');
 
-        $error = Mockery::mock('League\CLImate\Util\Writer\StdErr');
+        $error = Mockery::mock(StdErr::class);
         $error->shouldReceive('write')->once()->with('Oh, hey there.');
 
         $output = new Output();
@@ -148,9 +151,9 @@ public function it_can_take_existing_writer_keys_and_resolve_them()
     /** @test */
     public function it_can_get_the_available_writers()
     {
-        $out    = Mockery::mock('League\CLImate\Util\Writer\StdOut');
-        $error  = Mockery::mock('League\CLImate\Util\Writer\StdErr');
-        $buffer = Mockery::mock('League\CLImate\Util\Writer\Buffer');
+        $out    = Mockery::mock(StdOut::class);
+        $error  = Mockery::mock(StdErr::class);
+        $buffer = Mockery::mock(Buffer::class);
 
         $output = new Output();
 
@@ -185,7 +188,7 @@ public function it_can_get_the_available_writers()
     /** @test */
     public function it_will_yell_if_writer_does_not_implement_writer_interface()
     {
-        $out    = Mockery::mock('League\CLImate\Util\Writer\Wat');
+        $out    = Mockery::mock();
         $output = new Output();
 
         $this->expectException(InvalidArgumentException::class);
@@ -211,10 +214,10 @@ public function it_will_yell_if_trying_to_add_a_non_existent_nested_writer_key()
      */
     public function it_can_write_to_a_non_default_writer_once()
     {
-        $out = Mockery::mock('League\CLImate\Util\Writer\StdOut');
+        $out = Mockery::mock(StdOut::class);
         $out->shouldReceive('write')->once()->with('Second time.');
 
-        $error = Mockery::mock('League\CLImate\Util\Writer\StdErr');
+        $error = Mockery::mock(StdErr::class);
         $error->shouldReceive('write')->once()->with('First time.');
 
         $output = new Output();
@@ -234,10 +237,10 @@ public function it_can_write_to_a_non_default_writer_once()
      */
     public function it_will_persist_writer_if_told_to()
     {
-        $out = Mockery::mock('League\CLImate\Util\Writer\StdOut');
+        $out = Mockery::mock(StdOut::class);
         $out->shouldReceive('write')->once()->with('Second time.');
 
-        $error = Mockery::mock('League\CLImate\Util\Writer\StdErr');
+        $error = Mockery::mock(StdErr::class);
         $error->shouldReceive('write')->times(3)->with('First time.');
 
         $output = new Output();
@@ -258,7 +261,7 @@ public function it_will_persist_writer_if_told_to()
     /** @test */
     public function it_can_retrieve_a_writer()
     {
-        $buffer = Mockery::mock('League\CLImate\Util\Writer\Buffer');
+        $buffer = Mockery::mock(Buffer::class);
         $buffer->shouldReceive('write')->once()->with('Oh, hey there.');
         $buffer->shouldReceive('get')->once()->andReturn('Oh, hey there.');
 
diff --git a/tests/Util/System/LinuxTest.php b/tests/Util/System/LinuxTest.php
index 44d1b0a7..8d323e5c 100644
--- a/tests/Util/System/LinuxTest.php
+++ b/tests/Util/System/LinuxTest.php
@@ -3,6 +3,7 @@
 namespace League\CLImate\Tests\Util\System;
 
 use League\CLImate\Tests\TestBase;
+use League\CLImate\Util\System\Linux;
 use Mockery;
 
 class LinuxTest extends TestBase
@@ -10,7 +11,7 @@ class LinuxTest extends TestBase
     /** @test */
     public function it_can_get_the_width()
     {
-        $system = Mockery::mock('League\CLImate\Util\System\Linux')
+        $system = Mockery::mock(Linux::class)
                             ->makePartial()
                             ->shouldAllowMockingProtectedMethods();
 
@@ -22,7 +23,7 @@ public function it_can_get_the_width()
     /** @test */
     public function it_will_return_null_if_width_is_not_numeric()
     {
-        $system = Mockery::mock('League\CLImate\Util\System\Linux')
+        $system = Mockery::mock(Linux::class)
                             ->makePartial()
                             ->shouldAllowMockingProtectedMethods();
 
@@ -34,7 +35,7 @@ public function it_will_return_null_if_width_is_not_numeric()
     /** @test */
     public function it_can_get_the_height()
     {
-        $system = Mockery::mock('League\CLImate\Util\System\Linux')
+        $system = Mockery::mock(Linux::class)
                             ->makePartial()
                             ->shouldAllowMockingProtectedMethods();
 
@@ -46,7 +47,7 @@ public function it_can_get_the_height()
     /** @test */
     public function it_will_return_null_if_height_is_not_numeric()
     {
-        $system = Mockery::mock('League\CLImate\Util\System\Linux')
+        $system = Mockery::mock(Linux::class)
                             ->makePartial()
                             ->shouldAllowMockingProtectedMethods();
 
diff --git a/tests/Util/System/WindowsTest.php b/tests/Util/System/WindowsTest.php
index 19cd7fc0..46940251 100644
--- a/tests/Util/System/WindowsTest.php
+++ b/tests/Util/System/WindowsTest.php
@@ -2,6 +2,7 @@
 
 namespace League\CLImate\Tests\Util\System;
 
+use League\CLImate\Util\System\Windows;
 use League\CLImate\Tests\TestBase;
 use Mockery;
 
@@ -10,7 +11,7 @@ class WindowsTest extends TestBase
     /** @test */
     public function it_can_get_the_width()
     {
-        $system = Mockery::mock('League\CLImate\Util\System\Windows')
+        $system = Mockery::mock(Windows::class)
                             ->makePartial()
                             ->shouldAllowMockingProtectedMethods();
 
@@ -22,7 +23,7 @@ public function it_can_get_the_width()
     /** @test */
     public function it_will_return_null_if_width_is_not_numeric()
     {
-        $system = Mockery::mock('League\CLImate\Util\System\Windows')
+        $system = Mockery::mock(Windows::class)
                             ->makePartial()
                             ->shouldAllowMockingProtectedMethods();
 
@@ -34,7 +35,7 @@ public function it_will_return_null_if_width_is_not_numeric()
     /** @test */
     public function it_can_get_the_height()
     {
-        $system = Mockery::mock('League\CLImate\Util\System\Windows')
+        $system = Mockery::mock(Windows::class)
                             ->makePartial()
                             ->shouldAllowMockingProtectedMethods();
 
@@ -46,7 +47,7 @@ public function it_can_get_the_height()
     /** @test */
     public function it_will_return_null_if_height_is_not_numeric()
     {
-        $system = Mockery::mock('League\CLImate\Util\System\Windows')
+        $system = Mockery::mock(Windows::class)
                             ->makePartial()
                             ->shouldAllowMockingProtectedMethods();
 
diff --git a/tests/Util/Writer/FileTest.php b/tests/Util/Writer/FileTest.php
index 0bcb54ca..2fee91fe 100644
--- a/tests/Util/Writer/FileTest.php
+++ b/tests/Util/Writer/FileTest.php
@@ -8,6 +8,7 @@
 use League\CLImate\Exceptions\RuntimeException;
 use League\CLImate\Tests\TestBase;
 use League\CLImate\Util\Output;
+use League\CLImate\Util\Writer\File;
 use org\bovigo\vfs\vfsStream;
 
 class FileTest extends TestBase
@@ -23,7 +24,7 @@ public function setUp(): void
 
     protected function getFileMock()
     {
-        return \Mockery::mock('League\CLImate\Util\Writer\File', func_get_args())->makePartial();
+        return \Mockery::mock(File::class, func_get_args())->makePartial();
     }
 
     /** @test */