diff --git a/phpunit.xml.dist b/phpunit.xml.dist
index b2a738c28f..091271510f 100644
--- a/phpunit.xml.dist
+++ b/phpunit.xml.dist
@@ -29,4 +29,9 @@
         <ini name="display_errors" value="on"/>
         <ini name="display_startup_errors" value="on"/>
     </php>
+
+    <!-- logging>
+        <log type="coverage-clover" target="./unit-tests/output/clover.xml"/>
+        <log type="coverage-html" target="./unit-tests/output"/>
+    </logging -->
 </phpunit>
diff --git a/unit-tests/Zephir/Test/Command/CompileCommandTest.php b/unit-tests/Zephir/Test/Command/CompileCommandTest.php
new file mode 100644
index 0000000000..b4592db7a9
--- /dev/null
+++ b/unit-tests/Zephir/Test/Command/CompileCommandTest.php
@@ -0,0 +1,121 @@
+<?php
+
+/**
+ * This file is part of the Zephir.
+ *
+ * (c) Zephir Team <team@zephir-lang.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Zephir\Test\Command;
+
+use Symfony\Component\Console\Tester\CommandTester;
+use Symfony\Component\Console\Output\OutputInterface;
+use Zephir\Application;
+use Zephir\Command\CompileCommand;
+use Zephir\Di\Singleton;
+use Zephir\Support\TestCase;
+use function Zephir\unlink_recursive;
+
+/**
+ * Zephir\Test\Command\CompileCommandTest
+ *
+ * @package Zephir\Test\CompilerFile
+ */
+class CompileCommandTest extends TestCase
+{
+    /**
+     * Common directory.
+     * unit-tests/Zephir/Test/Command/CompileCommandTest.php
+     * @var string
+     */
+    private $pwd;
+
+    /**
+     * Store the current directory before to be change.
+     *
+     * @return void
+     */
+    public function setUp()
+    {
+        $this->pwd = getcwd();
+        Singleton::reset();
+    }
+
+    /**
+     * Restore current directory, and clean config.json.
+     *
+     * @return void
+     */
+    public function tearDown()
+    {
+        if (getcwd() !== $this->pwd) {
+            if (file_exists('.temp')) {
+                unlink_recursive('.temp/');
+            }
+
+            if (file_exists('ext')) {
+                unlink_recursive('ext/');
+            }
+
+            if (file_exists('compile.log')) {
+                unlink('compile.log');
+            }
+
+            if (file_exists('compile-errors.log')) {
+                unlink('compile-errors.log');
+            }
+
+            chdir($this->pwd);
+        }
+    }
+
+    /**
+     * @test
+     * @dataProvider devModeProvider
+     * @issue https://github.com/phalcon/zephir/issues/1520
+     *
+     * @param array  $mode
+     * @param string $cflags
+     */
+    public function shouldDetermineDevOption(array $mode, $cflags)
+    {
+        // TODO: Create a test for Windows
+        if (\strtoupper(\substr(PHP_OS, 0, 3)) === 'WIN') {
+            $this->markTestSkipped(
+                'This test currently works on Linux systems only'
+            );
+        }
+
+        chdir(ZEPHIRPATH . '/unit-tests/fixtures/devmode');
+
+        $application = new Application(ZEPHIRPATH);
+        $application->add(new CompileCommand());
+
+        Singleton::getDefault()->get('config')->set('silent', true);
+
+        $command = $application->find('compile');
+        $commandTester = new CommandTester($command);
+
+        ob_start();
+
+        $commandTester->execute(
+            ['command'  => $command->getName()] + $mode,
+            ['verbosity' => OutputInterface::VERBOSITY_QUIET]
+        );
+
+        ob_get_clean();
+
+        $this->assertRegexp("/CFLAGS='{$cflags}'/", file_get_contents('ext/config.nice'));
+    }
+
+    public function devModeProvider()
+    {
+        return [
+            [['--no-dev' => true], '-O2 -fvisibility=hidden -Wparentheses -flto -DZEPHIR_RELEASE=1'],
+            [['--dev' => true], '-O0 -g3'],
+        ];
+    }
+}
diff --git a/unit-tests/fixtures/devmode/config.json b/unit-tests/fixtures/devmode/config.json
new file mode 100644
index 0000000000..dead573a6d
--- /dev/null
+++ b/unit-tests/fixtures/devmode/config.json
@@ -0,0 +1,50 @@
+{
+    "stubs": {
+        "stubs-run-after-generate": false
+    },
+    "warnings": {
+        "unused-variable": true,
+        "unused-variable-external": false,
+        "possible-wrong-parameter": true,
+        "possible-wrong-parameter-undefined": false,
+        "nonexistent-function": true,
+        "nonexistent-class": true,
+        "non-valid-isset": true,
+        "non-array-update": true,
+        "non-valid-objectupdate": true,
+        "non-valid-fetch": true,
+        "invalid-array-index": true,
+        "non-array-append": true,
+        "invalid-return-type": true,
+        "unreachable-code": true,
+        "nonexistent-constant": true,
+        "not-supported-magic-constant": true,
+        "non-valid-decrement": true,
+        "non-valid-increment": true,
+        "non-valid-clone": true,
+        "non-valid-new": true,
+        "non-array-access": true,
+        "invalid-reference": true,
+        "invalid-typeof-comparison": true,
+        "conditional-initialization": true
+    },
+    "optimizations": {
+        "static-type-inference": true,
+        "static-type-inference-second-pass": true,
+        "local-context-pass": true,
+        "constant-folding": true,
+        "static-constant-class-folding": true,
+        "call-gatherer-pass": true,
+        "check-invalid-reads": false,
+        "internal-call-transformation": false
+    },
+    "namespace": "devmode",
+    "name": "devmode",
+    "description": "",
+    "author": "",
+    "version": "0.0.1",
+    "verbose": false,
+    "requires": {
+        "extensions": []
+    }
+}
diff --git a/unit-tests/fixtures/devmode/devmode/test.zep b/unit-tests/fixtures/devmode/devmode/test.zep
new file mode 100644
index 0000000000..dbd57f7459
--- /dev/null
+++ b/unit-tests/fixtures/devmode/devmode/test.zep
@@ -0,0 +1,5 @@
+namespace Devmode;
+
+class Test
+{
+}