diff --git a/config/runner.yml b/config/runner.yml
index 9d380200..793aaf00 100644
--- a/config/runner.yml
+++ b/config/runner.yml
@@ -37,6 +37,12 @@ drupal:
     config_dir: ~
     existing_config: false
     settings_override_file: "settings.override.php"
+    # Local development settings override.
+    # Add development settings that you want to share with your team and commit this file.
+    # If found this file will be copied in `/sites/{sites-subdir}/settings.local.php`,
+    # which should be, instead, git-ignored. This will give the possibility to locally
+    # tweak development settings.
+    settings_local_file: "${drupal.root}/sites/example.settings.local.php"
     # Setting this to "false" will run "site-install" without the "--db-url" parameter.
     # This is useful if the database settings are already set in your settings.php file.
     generate_db_url: true
diff --git a/src/Commands/AbstractDrupalCommands.php b/src/Commands/AbstractDrupalCommands.php
index 28e1592d..c1f2368e 100644
--- a/src/Commands/AbstractDrupalCommands.php
+++ b/src/Commands/AbstractDrupalCommands.php
@@ -27,9 +27,7 @@ abstract class AbstractDrupalCommands extends AbstractCommands implements Filesy
      */
     public function getDrupal()
     {
-        return $this->getConfig()->get('drupal.core') === 7 ?
-        new Drupal7Commands() :
-        new Drupal8Commands();
+        return $this->getConfig()->get('drupal.core') === 7 ? new Drupal7Commands() : new Drupal8Commands();
     }
 
     /**
@@ -341,12 +339,15 @@ public function drushSetup(array $options = [
      * @option root                     Drupal root.
      * @option sites-subdir             Drupal site subdirectory.
      * @option settings-override-file   Drupal site settings override filename.
-     * @option force                    Drupal force generation of a new settings.php.
-     * @option skip-permissions-setup   Drupal skip permissions setup.
+     * @option force                    Force generation of a new settings.php.
+     * @option skip-permissions-setup   Skip permissions setup.
+     * @option dev                      Development settings setup.
      *
      * @param array $options
      *
      * @return \Robo\Collection\CollectionBuilder
+     *
+     * @SuppressWarnings(PHPMD.CyclomaticComplexity)
      */
     public function settingsSetup(array $options = [
         'root' => InputOption::VALUE_REQUIRED,
@@ -354,21 +355,21 @@ public function settingsSetup(array $options = [
         'settings-override-file' => InputOption::VALUE_REQUIRED,
         'force' => false,
         'skip-permissions-setup' => false,
+        'dev' => false
     ])
     {
-        $settings_default_path = $options['root'] . '/sites/' . $options['sites-subdir'] . '/default.settings.php';
+        $settings_default_path = $options['root'] . '/sites/default/default.settings.php';
         $settings_path = $options['root'] . '/sites/' . $options['sites-subdir'] . '/settings.php';
         $settings_override_path = $options['root'] . '/sites/' . $options['sites-subdir'] . '/' . $options['settings-override-file'];
 
         // Save the filename of the override file in a single variable to use it
         // in the heredoc variable $custom_config hereunder.
         $settings_override_filename = $options['settings-override-file'];
-
         $custom_config = $this->getDrupal()->getSettingsSetupAddendum($settings_override_filename);
 
         $collection = [];
 
-        if (true === (bool) $options['force'] || !file_exists($settings_path)) {
+        if ((bool) $options['force'] || !file_exists($settings_path)) {
             $collection[] = $this->taskWriteToFile($settings_default_path)->append()->lines([$custom_config]);
             $collection[] = $this->taskFilesystemStack()->copy($settings_default_path, $settings_path, true);
         }
@@ -378,6 +379,19 @@ public function settingsSetup(array $options = [
             $this->getConfig()
         )->setConfigKey('drupal.settings');
 
+        // If ran in dev mode copy local settings file to 'settings.local.php'.
+        // Such file will be conditionally included in 'settings-override-file'.
+        if ($options['dev']) {
+            $local_settings_file = $this->getConfig()->get('drupal.site.settings_local_file');
+            if (file_exists($local_settings_file)) {
+                $local_settings_path = $options['root'] . '/sites/' . $options['sites-subdir'] . '/settings.local.php';
+                $collection[] = $this->taskFilesystemStack()->copy($local_settings_file, $local_settings_path, $options['force']);
+            }
+            $collection[] = $this->taskWriteToFile($settings_override_path)
+                ->append()
+                ->text($this->getDrupal()->getSettingsLocalSetupAddendum());
+        }
+
         if (!$options['skip-permissions-setup']) {
             $collection[] = $this->permissionsSetup($options);
         }
@@ -437,4 +451,24 @@ protected function processPrePostInstallCommands(array &$commands, array $tokens
             }
         }
     }
+
+    /**
+     * Get include portion for local development override configuration.
+     *
+     * This will be optionally appended to the settings override file.
+     *
+     * @return string
+     */
+    protected function getSettingsLocalSetupAddendum()
+    {
+        return <<< EOF
+
+/**
+ * Load local development override configuration, if available.
+ */
+if (file_exists(__DIR__ . '/settings.local.php')) {
+  include __DIR__ . '/settings.local.php';
+}
+EOF;
+    }
 }
diff --git a/tests/CommandsTest.php b/tests/CommandsTest.php
index 8408fee0..7837e70c 100644
--- a/tests/CommandsTest.php
+++ b/tests/CommandsTest.php
@@ -265,58 +265,39 @@ function $fct() {}
     }
 
     /**
-     * @param array $config
+     * @param array $configs
      * @param array $expected
      *
-     * @dataProvider settingsSetupForceDataProvider
+     * @dataProvider settingsSetupParametersDataProvider
      */
-    public function testSettingsSetupForce(array $config, array $expected)
+    public function testSettingsSetupParameters(array $configs, array $expected)
     {
-        $configFile = $this->getSandboxFilepath('runner.yml');
-        file_put_contents($configFile, Yaml::dump($config));
-
-        $sites_subdir = isset($config['drupal']['site']['sites_subdir']) ? $config['drupal']['site']['sites_subdir'] : 'default';
-        mkdir($this->getSandboxRoot() . '/build/sites/' . $sites_subdir . '/', 0777, true);
-        file_put_contents($this->getSandboxRoot() . '/build/sites/' . $sites_subdir . '/default.settings.php', '');
-        file_put_contents($this->getSandboxRoot() . '/build/sites/' . $sites_subdir . '/settings.php', '# Already existing file.');
-
-        $input = new StringInput('drupal:settings-setup --working-dir=' . $this->getSandboxRoot());
-
-        if (true === $config['drupal']['site']['force']) {
-            $input = new StringInput('drupal:settings-setup --working-dir=' . $this->getSandboxRoot() . ' --force');
+        $sites_subdir = isset($configs['drupal']['site']['sites_subdir']) ? $configs['drupal']['site']['sites_subdir'] : 'default';
+        mkdir($this->getSandboxRoot() . '/build/sites/default', 0755, true);
+        if ($sites_subdir !== 'default') {
+            mkdir($this->getSandboxRoot() . '/build/sites/' . $sites_subdir . '/', 0755, true);
         }
-        $runner = new TaskRunner($input, new BufferedOutput(), $this->getClassLoader());
-        $runner->run();
+        file_put_contents($this->getSandboxRoot() . '/build/sites/default/default.settings.php', '');
+        file_put_contents($this->getSandboxRoot() . '/build/sites/example.settings.local.php', '// Local development override configuration.');
 
-        foreach ($expected as $row) {
-            $content = file_get_contents($this->getSandboxFilepath($row['file']));
-            $this->assertContainsNotContains($content, $row);
+        if (!empty($configs['files'])) {
+            foreach ($configs['files'] as $file) {
+                file_put_contents($this->getSandboxRoot() . '/build/sites/' . $sites_subdir . '/' . $file['name'], $file['content']);
+            }
         }
 
-        // Generate a random function name.
-        $fct = $this->generateRandomString(20);
-
-        // Generate a dummy PHP code.
-        $config_override_dummy_script = <<< EOF
-<?php 
-function $fct() {}
-EOF;
-
-        $config_override_filename = isset($config['drupal']['site']['settings_override_file']) ?
-        $config['drupal']['site']['settings_override_file'] :
-        'settings.override.php';
-
-        // Add the dummy PHP code to the config override file.
-        file_put_contents(
-            $this->getSandboxRoot() . '/build/sites/' . $sites_subdir . '/' . $config_override_filename,
-            $config_override_dummy_script
-        );
-
-        // Include the config override file.
-        include_once $this->getSandboxRoot() . '/build/sites/' . $sites_subdir . '/' . $config_override_filename;
+        $input = 'drupal:settings-setup --working-dir=' . $this->getSandboxRoot() . ' --sites-subdir=' . $sites_subdir;
+        if (isset($configs['parameters']['force']) && $configs['parameters']['force']) {
+            $input .= ' --force';
+        }
+        if (isset($configs['parameters']['dev']) && $configs['parameters']['dev']) {
+            $input .= ' --dev';
+        }
+        $runner = new TaskRunner(new StringInput($input), new BufferedOutput(), $this->getClassLoader());
+        $exit_code = $runner->run();
+        $this->assertEquals(0, $exit_code, 'Command run returned an error.');
 
-        // Test if the dummy PHP code has been properly included.
-        $this->assertTrue(\function_exists($fct));
+        $this->processSettingsAssertions($expected);
     }
 
     /**
@@ -404,9 +385,9 @@ public function drupal8SettingsSetupDataProvider()
     /**
      * @return array
      */
-    public function settingsSetupForceDataProvider()
+    public function settingsSetupParametersDataProvider()
     {
-        return $this->getFixtureContent('commands/drupal-settings-setup-force.yml');
+        return $this->getFixtureContent('commands/drupal-settings-setup-parameters.yml');
     }
 
     /**
@@ -427,13 +408,35 @@ public function changelogDataProvider()
 
     /**
      * @param string $content
-     * @param array  $expected
+     * @param array  $expectations
      */
-    protected function assertContainsNotContains($content, array $expected)
+    protected function assertContainsNotContains($content, array $expectations)
     {
-        $this->assertContains($expected['contains'], $content);
+        if (!empty($expectations['contains'])) {
+            foreach ((array) $expectations['contains'] as $expected) {
+                $this->assertContains($expected, $content);
+            }
+        }
         if (!empty($expected['not_contains'])) {
-            $this->assertNotContains($expected['not_contains'], $content);
+            foreach ((array) $expectations['not_contains'] as $expected) {
+                $this->assertNotContains($expected, $content);
+            }
+        }
+    }
+
+    /**
+     * @param array $expected
+     */
+    protected function processSettingsAssertions(array $expected)
+    {
+        foreach ($expected as $row) {
+            if (isset($row['file'])) {
+                $content = file_get_contents($this->getSandboxFilepath($row['file']));
+                $this->assertContainsNotContains($content, $row);
+            }
+            if (isset($row['no_file'])) {
+                $this->assertFileNotExists($row['no_file']);
+            }
         }
     }
 }
diff --git a/tests/fixtures/commands/drupal-settings-setup-force.yml b/tests/fixtures/commands/drupal-settings-setup-force.yml
deleted file mode 100644
index be04d9d7..00000000
--- a/tests/fixtures/commands/drupal-settings-setup-force.yml
+++ /dev/null
@@ -1,17 +0,0 @@
-- configuration:
-    drupal:
-      site:
-        force: false
-  expected:
-    - file: "build/sites/default/settings.php"
-      contains: "# Already existing file."
-      not_contains: "include $app_root . '/' . $site_path . '/settings.override.php';"
-
-- configuration:
-    drupal:
-      site:
-        force: true
-  expected:
-    - file: "build/sites/default/settings.php"
-      contains: "include $app_root . '/' . $site_path . '/settings.override.php';"
-      not_contains: "# Already existing file."
diff --git a/tests/fixtures/commands/drupal-settings-setup-parameters.yml b/tests/fixtures/commands/drupal-settings-setup-parameters.yml
new file mode 100644
index 00000000..f5acb6a4
--- /dev/null
+++ b/tests/fixtures/commands/drupal-settings-setup-parameters.yml
@@ -0,0 +1,96 @@
+- configuration:
+    files:
+      - name: 'settings.php'
+        content: '# Already existing file.'
+    parameters:
+      force: false
+  expected:
+    - file: "build/sites/default/settings.php"
+      contains: "# Already existing file."
+      not_contains:
+        - "include $app_root . '/' . $site_path . '/settings.override.php';"
+        - "include $app_root . '/' . $site_path . '/settings.local.php';"
+    - no_file: "build/sites/default/settings.local.php"
+
+- configuration:
+    files:
+      - name: 'settings.php'
+        content: '# Already existing file.'
+    parameters:
+      force: true
+  expected:
+    - file: "build/sites/default/settings.php"
+      contains: "include $app_root . '/' . $site_path . '/settings.override.php';"
+      not_contains:
+        - "# Already existing file."
+        - "include $app_root . '/' . $site_path . '/settings.local.php';"
+    - no_file: "build/sites/default/settings.local.php"
+
+- configuration:
+    files:
+      - name: 'settings.php'
+        content: '# Already existing file.'
+      - name: 'settings.local.php'
+        content: '# Already existing file.'
+    parameters:
+      force: false
+      dev: true
+  expected:
+    - file: "build/sites/default/settings.php"
+      contains: "# Already existing file."
+      not_contains:
+        - "include $app_root . '/' . $site_path . '/settings.override.php';"
+        - "include $app_root . '/' . $site_path . '/settings.local.php';"
+    - file: "build/sites/default/settings.local.php"
+      contains: "# Already existing file."
+
+- configuration:
+    files:
+      - name: 'settings.php'
+        content: '# Already existing file.'
+      - name: 'settings.local.php'
+        content: '# Already existing file.'
+    parameters:
+      force: false
+      dev: true
+    drupal:
+      site:
+        sites_subdir: 'foo'
+  expected:
+    - file: "build/sites/foo/settings.php"
+      contains: "# Already existing file."
+      not_contains:
+        - "include $app_root . '/' . $site_path . '/settings.override.php';"
+        - "include $app_root . '/' . $site_path . '/settings.local.php';"
+    - file: "build/sites/foo/settings.local.php"
+      contains: "# Already existing file."
+
+- configuration:
+    files:
+      - name: 'settings.php'
+        content: '# Already existing file.'
+      - name: 'settings.local.php'
+        content: '# Already existing file.'
+    parameters:
+      force: true
+      dev: true
+  expected:
+    - file: "build/sites/default/settings.override.php"
+      contains:
+        - "include __DIR__ . '/settings.local.php';"
+      not_contains: "# Already existing file."
+    - file: "build/sites/default/settings.local.php"
+      contains: "// Local development override configuration."
+
+- configuration:
+    files:
+      - name: 'settings.local.php'
+        content: '// Initial config.'
+    parameters:
+      force: false
+  expected:
+    - file: "build/sites/default/settings.php"
+      not_contains: "include $app_root . '/' . $site_path . '/settings.local.php';"
+      contains: "include $app_root . '/' . $site_path . '/settings.override.php';"
+    - file: "build/sites/default/settings.local.php"
+      contains: "// Initial config."