diff --git a/drush/provision_git.drush.inc b/drush/provision_git.drush.inc
index 303fe8f..a449c4f 100644
--- a/drush/provision_git.drush.inc
+++ b/drush/provision_git.drush.inc
@@ -306,6 +306,48 @@ function drush_provision_git_clone($git_url = '', $path = '', $git_ref = '') {
     // The command failed
     return drush_set_error('DRUSH_PROVISION_GIT_CLONE_FAILED', dt("Git clone failed! \nThe specific errors are below:\n!errors", array('!errors' => implode("\n", drush_shell_exec_output()))));
   }
+
+  drush_log('Checking for Composer lock file in repository.');
+  chdir($path);
+  if (file_exists('composer.lock')) {
+    drush_log('Found Composer lock file. Installing dependencies. This may take awhile.');
+    #$command = 'composer install --no-progress --prefer-dist --no-interaction --no-suggest';
+    $command = 'COMPOSER_CACHE_DIR=/var/aegir/platform/.composer-cache-dir composer install --no-progress --prefer-dist --no-interaction --no-suggest';
+    if (_provision_git_exec($command)) {
+      drush_log(dt('Installed dependencies.'), 'ok');
+    }
+    else {
+      return drush_log(dt('Composer install failed to complete without errors! Your platform is likely broken until dependencies are fully installed. Try running the following commands: :composer_install', array(':composer_install' => "cd {$path}; composer install")), 'warning');
+    }
+  }
+}
+
+function _provision_git_exec($command) {
+  drush_log('Running: ' . $command, 'debug');
+  $descriptorspec = array(
+    0 => array("pipe", "r"), // stdin
+    1 => array("pipe", "w"), // stdout
+    2 => array("pipe", "w"), // stderr
+  );
+  $process = proc_open($command, $descriptorspec, $pipes, realpath('./'));
+  if (is_resource($process)) {
+    $sockets = array($pipes[1], $pipes[2]);
+    while (stream_select($sockets, $write = NULL, $except = NULL, $timeout = 300)) {
+      foreach ($sockets as $socket) {
+        if (!feof($socket) && $output = fgets($socket)) {
+          drush_log($output, 'info');
+        }
+        else {
+          if (proc_close($process)) {
+            drush_log('Finished running: ' . $command, 'debug');
+          }
+          else {
+            return drush_log(dt('An error occured when running command!'), 'warning');
+          }
+        }
+      }
+    }
+  }
 }
 
 /**