diff --git a/doc/03-cli.md b/doc/03-cli.md
index e8ea3672c..79a8d0b78 100644
--- a/doc/03-cli.md
+++ b/doc/03-cli.md
@@ -485,6 +485,13 @@ php composer.phar show monolog/monolog 1.0.2
 * **--direct (-D):** Restricts the list of packages to your direct dependencies.
 * **--strict:** Return a non-zero exit code when there are outdated packages.
 * **--format (-f):** Lets you pick between text (default) or json output format.
+* **--ignore-platform-reqs:** ignore all platform requirements (`php`, `hhvm`,
+  `lib-*` and `ext-*`) and force the installation even if the local machine does
+  not fulfill these. Use with the --outdated option.
+* **--ignore-platform-req:** ignore a specific platform requirement(`php`,
+  `hhvm`, `lib-*` and `ext-*`) and force the installation even if the local machine
+  does not fulfill it. Multiple requirements can be ignored via wildcard. Use with
+  the --outdated option.
 
 ## outdated
 
@@ -508,6 +515,12 @@ The color coding is as such:
 * **--format (-f):** Lets you pick between text (default) or json output format.
 * **--no-dev:** Do not show outdated dev dependencies.
 * **--locked:** Shows updates for packages from the lock file, regardless of what is currently in vendor dir.
+* **--ignore-platform-reqs:** ignore all platform requirements (`php`, `hhvm`,
+  `lib-*` and `ext-*`) and force the installation even if the local machine does
+  not fulfill these.
+* **--ignore-platform-req:** ignore a specific platform requirement(`php`,
+  `hhvm`, `lib-*` and `ext-*`) and force the installation even if the local machine
+  does not fulfill it. Multiple requirements can be ignored via wildcard.
 
 ## browse / home
 
diff --git a/src/Composer/Command/OutdatedCommand.php b/src/Composer/Command/OutdatedCommand.php
index 0b38f2f0e..503541584 100644
--- a/src/Composer/Command/OutdatedCommand.php
+++ b/src/Composer/Command/OutdatedCommand.php
@@ -42,6 +42,8 @@ class OutdatedCommand extends ShowCommand
                 new InputOption('format', 'f', InputOption::VALUE_REQUIRED, 'Format of the output: text or json', 'text'),
                 new InputOption('ignore', null, InputOption::VALUE_REQUIRED | InputOption::VALUE_IS_ARRAY, 'Ignore specified package(s). Use it with the --outdated option if you don\'t want to be informed about new versions of some packages.'),
                 new InputOption('no-dev', null, InputOption::VALUE_NONE, 'Disables search in require-dev packages.'),
+                new InputOption('ignore-platform-req', null, InputOption::VALUE_REQUIRED | InputOption::VALUE_IS_ARRAY, 'Ignore a specific platform requirement (php & ext- packages). Use with the --outdated option'),
+                new InputOption('ignore-platform-reqs', null, InputOption::VALUE_NONE, 'Ignore all platform requirements (php & ext- packages). Use with the --outdated option'),
             ))
             ->setHelp(
                 <<<EOT
@@ -88,6 +90,12 @@ EOT
         if ($input->getOption('no-dev')) {
             $args['--no-dev'] = true;
         }
+        if ($input->getOption('ignore-platform-req')) {
+            $args['--ignore-platform-req'] = $input->getOption('ignore-platform-req');
+        }
+        if ($input->getOption('ignore-platform-reqs')) {
+            $args['--ignore-platform-reqs'] = true;
+        }
         $args['--format'] = $input->getOption('format');
         $args['--ignore'] = $input->getOption('ignore');
 
diff --git a/src/Composer/Command/ShowCommand.php b/src/Composer/Command/ShowCommand.php
index 8f80f2808..dae6ac70b 100644
--- a/src/Composer/Command/ShowCommand.php
+++ b/src/Composer/Command/ShowCommand.php
@@ -14,6 +14,7 @@ namespace Composer\Command;
 
 use Composer\Composer;
 use Composer\DependencyResolver\DefaultPolicy;
+use Composer\Filter\PlatformRequirementFilter\PlatformRequirementFilterFactory;
 use Composer\Json\JsonFile;
 use Composer\Package\BasePackage;
 use Composer\Package\CompletePackageInterface;
@@ -88,6 +89,8 @@ class ShowCommand extends BaseCommand
                 new InputOption('strict', null, InputOption::VALUE_NONE, 'Return a non-zero exit code when there are outdated packages'),
                 new InputOption('format', 'f', InputOption::VALUE_REQUIRED, 'Format of the output: text or json', 'text'),
                 new InputOption('no-dev', null, InputOption::VALUE_NONE, 'Disables search in require-dev packages.'),
+                new InputOption('ignore-platform-req', null, InputOption::VALUE_REQUIRED | InputOption::VALUE_IS_ARRAY, 'Ignore a specific platform requirement (php & ext- packages). Use with the --outdated option'),
+                new InputOption('ignore-platform-reqs', null, InputOption::VALUE_NONE, 'Ignore all platform requirements (php & ext- packages). Use with the --outdated option'),
             ))
             ->setHelp(
                 <<<EOT
@@ -151,6 +154,8 @@ EOT
             return 1;
         }
 
+        $ignorePlatformReqs = $input->getOption('ignore-platform-reqs') ?: ($input->getOption('ignore-platform-req') ?: false);
+
         // init repos
         $platformOverrides = array();
         if ($composer) {
@@ -267,7 +272,7 @@ EOT
             } else {
                 $latestPackage = null;
                 if ($input->getOption('latest')) {
-                    $latestPackage = $this->findLatestPackage($package, $composer, $platformRepo, $input->getOption('minor-only'));
+                    $latestPackage = $this->findLatestPackage($package, $composer, $platformRepo, $input->getOption('minor-only'), $ignorePlatformReqs);
                 }
                 if (
                     $input->getOption('outdated')
@@ -387,7 +392,7 @@ EOT
                 if ($showLatest && $showVersion) {
                     foreach ($packages[$type] as $package) {
                         if (is_object($package)) {
-                            $latestPackage = $this->findLatestPackage($package, $composer, $platformRepo, $showMinorOnly);
+                            $latestPackage = $this->findLatestPackage($package, $composer, $platformRepo, $showMinorOnly, $ignorePlatformReqs);
                             if ($latestPackage === false) {
                                 continue;
                             }
@@ -1248,10 +1253,11 @@ EOT
      * Given a package, this finds the latest package matching it
      *
      * @param bool $minorOnly
+     * @param bool|string $ignorePlatformReqs
      *
      * @return PackageInterface|false
      */
-    private function findLatestPackage(PackageInterface $package, Composer $composer, PlatformRepository $platformRepo, $minorOnly = false)
+    private function findLatestPackage(PackageInterface $package, Composer $composer, PlatformRepository $platformRepo, $minorOnly = false, $ignorePlatformReqs = false)
     {
         // find the latest version allowed in this repo set
         $name = $package->getName();
@@ -1276,7 +1282,7 @@ EOT
             $targetVersion = '^' . $package->getVersion();
         }
 
-        $candidate = $versionSelector->findBestCandidate($name, $targetVersion, $bestStability);
+        $candidate = $versionSelector->findBestCandidate($name, $targetVersion, $bestStability, PlatformRequirementFilterFactory::fromBoolOrList($ignorePlatformReqs));
         while ($candidate instanceof AliasPackage) {
             $candidate = $candidate->getAliasOf();
         }