diff --git a/src/Composer/Autoload/AutoloadGenerator.php b/src/Composer/Autoload/AutoloadGenerator.php
index 971702edb..e725330a1 100644
--- a/src/Composer/Autoload/AutoloadGenerator.php
+++ b/src/Composer/Autoload/AutoloadGenerator.php
@@ -582,7 +582,7 @@ HEADER;
             $file .= <<<'INCLUDE_PATH'
         $includePaths = require __DIR__ . '/include_paths.php';
         array_push($includePaths, get_include_path());
-        set_include_path(join(PATH_SEPARATOR, $includePaths));
+        set_include_path(implode(PATH_SEPARATOR, $includePaths));
 
 
 INCLUDE_PATH;
diff --git a/src/Composer/Command/ShowCommand.php b/src/Composer/Command/ShowCommand.php
index a0a010f54..7241b1ef8 100644
--- a/src/Composer/Command/ShowCommand.php
+++ b/src/Composer/Command/ShowCommand.php
@@ -463,7 +463,7 @@ EOT
         $io = $this->getIO();
         $io->write('<info>name</info>     : ' . $package->getPrettyName());
         $io->write('<info>descrip.</info> : ' . $package->getDescription());
-        $io->write('<info>keywords</info> : ' . join(', ', $package->getKeywords() ?: array()));
+        $io->write('<info>keywords</info> : ' . implode(', ', $package->getKeywords() ?: array()));
         $this->printVersions($package, $versions, $installedRepo);
         if ($latestPackage) {
             $style = $this->getVersionStyle($latestPackage, $package);
diff --git a/src/Composer/IO/ConsoleIO.php b/src/Composer/IO/ConsoleIO.php
index b09ed0582..7cd6fd71a 100644
--- a/src/Composer/IO/ConsoleIO.php
+++ b/src/Composer/IO/ConsoleIO.php
@@ -158,13 +158,13 @@ class ConsoleIO extends BaseIO
 
         if (true === $stderr && $this->output instanceof ConsoleOutputInterface) {
             $this->output->getErrorOutput()->write($messages, $newline, $sfVerbosity);
-            $this->lastMessageErr = join($newline ? "\n" : '', (array) $messages);
+            $this->lastMessageErr = implode($newline ? "\n" : '', (array) $messages);
 
             return;
         }
 
         $this->output->write($messages, $newline, $sfVerbosity);
-        $this->lastMessage = join($newline ? "\n" : '', (array) $messages);
+        $this->lastMessage = implode($newline ? "\n" : '', (array) $messages);
     }
 
     /**
@@ -193,7 +193,7 @@ class ConsoleIO extends BaseIO
     private function doOverwrite($messages, $newline, $size, $stderr, $verbosity)
     {
         // messages can be an array, let's convert it to string anyway
-        $messages = join($newline ? "\n" : '', (array) $messages);
+        $messages = implode($newline ? "\n" : '', (array) $messages);
 
         // since overwrite is supposed to overwrite last message...
         if (!isset($size)) {
diff --git a/tests/Composer/Test/Autoload/Fixtures/autoload_real_functions_with_include_paths.php b/tests/Composer/Test/Autoload/Fixtures/autoload_real_functions_with_include_paths.php
index e63c75cb5..2d66e4dc0 100644
--- a/tests/Composer/Test/Autoload/Fixtures/autoload_real_functions_with_include_paths.php
+++ b/tests/Composer/Test/Autoload/Fixtures/autoload_real_functions_with_include_paths.php
@@ -25,7 +25,7 @@ class ComposerAutoloaderInitFilesAutoload
 
         $includePaths = require __DIR__ . '/include_paths.php';
         array_push($includePaths, get_include_path());
-        set_include_path(join(PATH_SEPARATOR, $includePaths));
+        set_include_path(implode(PATH_SEPARATOR, $includePaths));
 
         $useStaticLoader = PHP_VERSION_ID >= 50600 && !defined('HHVM_VERSION');
         if ($useStaticLoader) {