diff --git a/tests/Issues/MozartIssue124Test.php b/tests/Issues/MozartIssue124Test.php
new file mode 100644
index 00000000..b2afbfc1
--- /dev/null
+++ b/tests/Issues/MozartIssue124Test.php
@@ -0,0 +1,124 @@
+<?php
+/**
+ *
+ * @see https://github.com/coenjacobs/mozart/blob/3b1243ca8505fa6436569800dc34269178930f39/tests/replacers/NamespaceReplacerIntegrationTest.php
+ */
+
+namespace BrianHenryIE\Strauss\Tests\Issues;
+
+use BrianHenryIE\Strauss\Console\Commands\Compose;
+
+use Symfony\Component\Console\Input\InputInterface;
+use Symfony\Component\Console\Output\OutputInterface;
+use BrianHenryIE\Strauss\Tests\Integration\Util\IntegrationTestCase;
+
+/**
+ * Class MozartIssue124Test
+ * @coversNothing
+ */
+class MozartIssue124Test extends IntegrationTestCase
+{
+
+    /**
+     * After PR #84, running Mozart on Mpdf began prefixing the class name inside the namespaced file.
+     *
+     * The problem coming from the filename matching the namespace name?
+     *
+     * dev-master#5d8041fdefc94ff57edcbe83ab468a9988c4fc11
+     *
+     * @see https://github.com/coenjacobs/mozart/pull/84/files
+     *
+     * Should be: "class Mpdf implements" because its namespace has already been prefixed.
+     */
+    public function test_it_does_not_make_classname_replacement_inside_namespaced_file()
+    {
+
+        $composerJsonString = <<<'EOD'
+{
+	"name": "brianhenryie/mozart-issue-124",
+	"require": {
+		"mpdf/mpdf": "8.0.10"
+	},
+	"extra": {
+		"strauss": {
+			"namespace_prefix": "BrianHenryIE\\Strauss\\",
+			"classmap_prefix": "BrianHenryIE_Strauss_"
+		}
+	}
+}
+EOD;
+
+        file_put_contents($this->testsWorkingDir . '/composer.json', $composerJsonString);
+
+        chdir($this->testsWorkingDir);
+
+        exec('composer install');
+
+        $inputInterfaceMock = $this->createMock(InputInterface::class);
+        $outputInterfaceMock = $this->createMock(OutputInterface::class);
+
+        $mozartCompose = new Compose();
+
+        $mozartCompose->run($inputInterfaceMock, $outputInterfaceMock);
+
+        $mpdf_php = file_get_contents($this->testsWorkingDir .'strauss/mpdf/mpdf/src/Mpdf.php');
+
+        // Confirm problem is gone.
+        $this->assertStringNotContainsString('class BrianHenryIE\Strauss\Mpdf implements', $mpdf_php);
+
+        // Confirm solution is correct.
+        $this->assertStringContainsString('class Mpdf implements', $mpdf_php);
+    }
+
+
+    /**
+     * Another Mpdf problem, presumably down to the classname matching the namespace.
+     *
+     * Typed function properties whose class type (name) match the namespace being replaced are
+     * unintentionally prefixed, causing PHP to crash.
+     *
+     * Occurring at dev-master#3b1243ca8505fa6436569800dc34269178930f39
+     *
+     * @see https://github.com/coenjacobs/mozart/issues/124
+     */
+    public function test_it_does_not_prefix_function_argument_types_whose_classname_matches_the_namespace()
+    {
+
+
+        $composerJsonString = <<<'EOD'
+{
+	"name": "brianhenryie/mozart-issue-124",
+	"require": {
+		"mpdf/mpdf": "8.0.10"
+	},
+	"extra": {
+		"strauss": {
+			"namespace_prefix": "BrianHenryIE\\Strauss\\",
+			"classmap_prefix": "BrianHenryIE_Strauss_"
+		}
+	}
+}
+EOD;
+
+        file_put_contents($this->testsWorkingDir . '/composer.json', $composerJsonString);
+
+        chdir($this->testsWorkingDir);
+
+        exec('composer install');
+
+        $inputInterfaceMock = $this->createMock(InputInterface::class);
+        $outputInterfaceMock = $this->createMock(OutputInterface::class);
+
+        $mozartCompose = new Compose();
+
+        $mozartCompose->run($inputInterfaceMock, $outputInterfaceMock);
+
+        $mpdf_php = file_get_contents($this->testsWorkingDir .'/strauss/mpdf/mpdf/src/Conversion/DecToOther.php');
+
+        // Confirm problem is gone.
+        $this->assertStringNotContainsString('public function __construct(BrianHenryIE\Strauss\Mpdf $mpdf)', $mpdf_php);
+
+        // Confirm solution is correct.
+        $this->assertStringContainsString('public function __construct(Mpdf $mpdf)', $mpdf_php);
+    }
+}