diff --git a/.travis.yml b/.travis.yml
index 7dc650bd..b9517101 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -24,7 +24,14 @@ before_install:
 
 install:
   - composer global require hirak/prestissimo
-  - $COMPOSER_UP
+  - |
+    if [[ "$SETUP" = "high" ]]; then
+      $COMPOSER_UP
+    elif [[ "$SETUP" = "lowest" ]]; then
+      $COMPOSER_UP --prefer-lowest --prefer-stable;
+    else
+      $COMPOSER_UP
+    fi
 
 before_script:
   - wget https://cdn.rawgit.com/prisis/43a2a7b137998ac92e24ee4daaa8e296/raw/681b89b8e156750de46558ead661509c468fb9a2/try_catch.sh -P ./build/travis
@@ -34,10 +41,19 @@ script:
   - ./build/travis/script.sh
 
 jobs:
+  fast_finish: true
+  allow_failures:
+    - php: nightly
   include:
     - stage: Test
       php: 7.2
-      env: PHPUNIT=true REMOVE_XDEBUG=true
+      env: PHPUNIT=true SETUP=high REMOVE_XDEBUG=true
+    - stage: Test
+      php: 7.2
+      env: PHPUNIT=true SETUP=lowest REMOVE_XDEBUG=true
+    - stage: Test
+      php: nightly
+      env: PHPUNIT=true SETUP=high REMOVE_XDEBUG=true
 
     - stage: Coding standard
       php: 7.2
diff --git a/composer.json b/composer.json
index b04ba8b8..d9b112e9 100644
--- a/composer.json
+++ b/composer.json
@@ -26,7 +26,7 @@
         "composer-plugin-api": "^1.0"
     },
     "require-dev": {
-        "composer/composer": "^1.6.0",
+        "composer/composer": "^1.6.0 || ^1.7.0",
         "mockery/mockery": "^1.0.0",
         "narrowspark/coding-standard": "^1.1.0",
         "narrowspark/testing-helper": "^6.0.0",
diff --git a/composer.lock b/composer.lock
index 82c06deb..0b39234c 100644
--- a/composer.lock
+++ b/composer.lock
@@ -4,7 +4,7 @@
         "Read more about it at https://getcomposer.org/doc/01-basic-usage.md#installing-dependencies",
         "This file is @generated automatically"
     ],
-    "content-hash": "339e72430f8a5d3eaf85070e9a801127",
+    "content-hash": "082e3456e8b919a53459f5c775aa9a9c",
     "packages": [],
     "packages-dev": [
         {
@@ -65,26 +65,26 @@
         },
         {
             "name": "composer/composer",
-            "version": "1.6.5",
+            "version": "1.7.0",
             "source": {
                 "type": "git",
                 "url": "https://github.com/composer/composer.git",
-                "reference": "b184a92419cc9a9c4c6a09db555a94d441cb11c9"
+                "reference": "39edb2f375679a4eba19e69e9c9491e302976983"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/composer/composer/zipball/b184a92419cc9a9c4c6a09db555a94d441cb11c9",
-                "reference": "b184a92419cc9a9c4c6a09db555a94d441cb11c9",
+                "url": "https://api.github.com/repos/composer/composer/zipball/39edb2f375679a4eba19e69e9c9491e302976983",
+                "reference": "39edb2f375679a4eba19e69e9c9491e302976983",
                 "shasum": ""
             },
             "require": {
                 "composer/ca-bundle": "^1.0",
                 "composer/semver": "^1.0",
                 "composer/spdx-licenses": "^1.2",
+                "composer/xdebug-handler": "^1.1",
                 "justinrainbow/json-schema": "^3.0 || ^4.0 || ^5.0",
                 "php": "^5.3.2 || ^7.0",
                 "psr/log": "^1.0",
-                "seld/cli-prompt": "^1.0",
                 "seld/jsonlint": "^1.4",
                 "seld/phar-utils": "^1.0",
                 "symfony/console": "^2.7 || ^3.0 || ^4.0",
@@ -110,7 +110,7 @@
             "type": "library",
             "extra": {
                 "branch-alias": {
-                    "dev-master": "1.6-dev"
+                    "dev-master": "1.7-dev"
                 }
             },
             "autoload": {
@@ -141,7 +141,7 @@
                 "dependency",
                 "package"
             ],
-            "time": "2018-05-04T09:44:59+00:00"
+            "time": "2018-08-03T13:39:07+00:00"
         },
         {
             "name": "composer/semver",
@@ -2909,16 +2909,16 @@
         },
         {
             "name": "phpunit/phpunit",
-            "version": "7.2.7",
+            "version": "7.3.0",
             "source": {
                 "type": "git",
                 "url": "https://github.com/sebastianbergmann/phpunit.git",
-                "reference": "8e878aff7917ef66e702e03d1359b16eee254e2c"
+                "reference": "0b6b29faf95c03fd7867e866438b78d5692b6f03"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/sebastianbergmann/phpunit/zipball/8e878aff7917ef66e702e03d1359b16eee254e2c",
-                "reference": "8e878aff7917ef66e702e03d1359b16eee254e2c",
+                "url": "https://api.github.com/repos/sebastianbergmann/phpunit/zipball/0b6b29faf95c03fd7867e866438b78d5692b6f03",
+                "reference": "0b6b29faf95c03fd7867e866438b78d5692b6f03",
                 "shasum": ""
             },
             "require": {
@@ -2963,7 +2963,7 @@
             "type": "library",
             "extra": {
                 "branch-alias": {
-                    "dev-master": "7.2-dev"
+                    "dev-master": "7.3-dev"
                 }
             },
             "autoload": {
@@ -2989,7 +2989,7 @@
                 "testing",
                 "xunit"
             ],
-            "time": "2018-07-15T05:20:50+00:00"
+            "time": "2018-08-03T06:02:45+00:00"
         },
         {
             "name": "psr/container",
@@ -3806,54 +3806,6 @@
             "homepage": "https://github.com/sebastianbergmann/version",
             "time": "2016-10-03T07:35:21+00:00"
         },
-        {
-            "name": "seld/cli-prompt",
-            "version": "1.0.3",
-            "source": {
-                "type": "git",
-                "url": "https://github.com/Seldaek/cli-prompt.git",
-                "reference": "a19a7376a4689d4d94cab66ab4f3c816019ba8dd"
-            },
-            "dist": {
-                "type": "zip",
-                "url": "https://api.github.com/repos/Seldaek/cli-prompt/zipball/a19a7376a4689d4d94cab66ab4f3c816019ba8dd",
-                "reference": "a19a7376a4689d4d94cab66ab4f3c816019ba8dd",
-                "shasum": ""
-            },
-            "require": {
-                "php": ">=5.3"
-            },
-            "type": "library",
-            "extra": {
-                "branch-alias": {
-                    "dev-master": "1.x-dev"
-                }
-            },
-            "autoload": {
-                "psr-4": {
-                    "Seld\\CliPrompt\\": "src/"
-                }
-            },
-            "notification-url": "https://packagist.org/downloads/",
-            "license": [
-                "MIT"
-            ],
-            "authors": [
-                {
-                    "name": "Jordi Boggiano",
-                    "email": "j.boggiano@seld.be"
-                }
-            ],
-            "description": "Allows you to prompt for user input on the command line, and optionally hide the characters they type",
-            "keywords": [
-                "cli",
-                "console",
-                "hidden",
-                "input",
-                "prompt"
-            ],
-            "time": "2017-03-18T11:32:45+00:00"
-        },
         {
             "name": "seld/jsonlint",
             "version": "1.7.1",
diff --git a/tests/Automatic/AutomaticTest.php b/tests/Automatic/AutomaticTest.php
index 065eb184..3273d927 100644
--- a/tests/Automatic/AutomaticTest.php
+++ b/tests/Automatic/AutomaticTest.php
@@ -19,6 +19,7 @@
 use Composer\Plugin\PluginManager;
 use Composer\Repository\RepositoryManager;
 use Composer\Repository\WritableRepositoryInterface;
+use Composer\Util\RemoteFilesystem;
 use Narrowspark\Automatic\Automatic;
 use Narrowspark\Automatic\Common\Traits\GetGenericPropertyReaderTrait;
 use Narrowspark\Automatic\Configurator;
@@ -155,9 +156,11 @@ public function testActivate(): void
             ->with(\Mockery::type(RepositoryManager::class))
             ->once();
 
-        $this->ioMock->shouldReceive('writeError')
-            ->once()
-            ->with('Composer >=1.7 not found, downloads will happen in sequence', true, IOInterface::DEBUG);
+        if (! \method_exists(RemoteFilesystem::class, 'getRemoteContents')) {
+            $this->ioMock->shouldReceive('writeError')
+                ->once()
+                ->with('Composer >=1.7 not found, downloads will happen in sequence', true, IOInterface::DEBUG);
+        }
 
         $inputMock = $this->mock(InputInterface::class);
         $inputMock->shouldReceive('getFirstArgument')
diff --git a/tests/Automatic/Installer/QuestionInstallationManagerTest.php b/tests/Automatic/Installer/QuestionInstallationManagerTest.php
index b2e74fe1..5aeaac09 100644
--- a/tests/Automatic/Installer/QuestionInstallationManagerTest.php
+++ b/tests/Automatic/Installer/QuestionInstallationManagerTest.php
@@ -13,6 +13,7 @@
 use Composer\Repository\RepositoryManager;
 use Composer\Repository\WritableRepositoryInterface;
 use Composer\Semver\VersionParser;
+use Composer\Util\RemoteFilesystem;
 use Mockery\MockInterface;
 use Narrowspark\Automatic\Common\Contract\Exception\InvalidArgumentException;
 use Narrowspark\Automatic\Common\Contract\Exception\RuntimeException;
diff --git a/tests/Automatic/Prefetcher/ParallelDownloaderTest.php b/tests/Automatic/Prefetcher/ParallelDownloaderTest.php
index ee34d0f4..ab768046 100644
--- a/tests/Automatic/Prefetcher/ParallelDownloaderTest.php
+++ b/tests/Automatic/Prefetcher/ParallelDownloaderTest.php
@@ -3,6 +3,7 @@
 namespace Narrowspark\Automatic\Test\Prefetcher;
 
 use Composer\IO\IOInterface;
+use Composer\Util\RemoteFilesystem;
 use Narrowspark\Automatic\Prefetcher\ParallelDownloader;
 use Narrowspark\Automatic\Test\Traits\ArrangeComposerClasses;
 use Narrowspark\TestingHelper\Phpunit\MockeryTestCase;
@@ -28,9 +29,11 @@ protected function setUp(): void
 
         $this->arrangeComposerClasses();
 
-        $this->ioMock->shouldReceive('writeError')
-            ->once()
-            ->with('Composer >=1.7 not found, downloads will happen in sequence', true, IOInterface::DEBUG);
+        if (! \method_exists(RemoteFilesystem::class, 'getRemoteContents')) {
+            $this->ioMock->shouldReceive('writeError')
+                ->once()
+                ->with('Composer >=1.7 not found, downloads will happen in sequence', true, IOInterface::DEBUG);
+        }
 
         $this->parallelDownloader = new ParallelDownloader($this->ioMock, $this->configMock);
     }
diff --git a/tests/Automatic/Traits/ArrangeComposerClasses.php b/tests/Automatic/Traits/ArrangeComposerClasses.php
index b262452f..b6908d51 100644
--- a/tests/Automatic/Traits/ArrangeComposerClasses.php
+++ b/tests/Automatic/Traits/ArrangeComposerClasses.php
@@ -5,6 +5,7 @@
 use Composer\Composer;
 use Composer\Config;
 use Composer\IO\IOInterface;
+use Composer\Util\RemoteFilesystem;
 use Narrowspark\Automatic\Lock;
 use Symfony\Component\Console\Input\InputInterface;
 
@@ -55,8 +56,17 @@ protected function arrangePackagist(): void
             ->andReturn(false);
         $this->ioMock->shouldReceive('writeError')
             ->with('Downloading https://packagist.org/packages.json', true, IOInterface::DEBUG);
-        $this->ioMock->shouldReceive('writeError')
-            ->once()
-            ->with('Writing ' . $this->composerCachePath . '/repo/https---packagist.org/packages.json into cache', true, IOInterface::DEBUG);
+
+        if (! \method_exists(RemoteFilesystem::class, 'getRemoteContents')) {
+            $this->ioMock->shouldReceive('writeError')
+                ->once()
+                ->with('Writing ' . $this->composerCachePath . '/repo/https---packagist.org/packages.json into cache', true, IOInterface::DEBUG);
+        } else {
+            $this->ioMock->shouldReceive('writeError')
+                ->with('Downloading https://repo.packagist.org/packages.json', true, IOInterface::DEBUG);
+            $this->ioMock->shouldReceive('writeError')
+                ->once()
+                ->with('Writing ' . $this->composerCachePath . '/repo/https---repo.packagist.org/packages.json into cache', true, IOInterface::DEBUG);
+        }
     }
 }