diff --git a/src/Composer/Command/ShowCommand.php b/src/Composer/Command/ShowCommand.php
index ae2307e5c..ec0261acc 100644
--- a/src/Composer/Command/ShowCommand.php
+++ b/src/Composer/Command/ShowCommand.php
@@ -467,7 +467,7 @@ EOT
                     }
                     $io->write('');
                     if (isset($package['warning'])) {
-                        $io->write('<warning>' . $package['warning'] . '</warning>');
+                        $io->writeError('<warning>' . $package['warning'] . '</warning>');
                     }
                 }