diff --git a/src/Composer/EventDispatcher/EventDispatcher.php b/src/Composer/EventDispatcher/EventDispatcher.php
index be53cab9d..faedb969a 100644
--- a/src/Composer/EventDispatcher/EventDispatcher.php
+++ b/src/Composer/EventDispatcher/EventDispatcher.php
@@ -243,6 +243,8 @@ class EventDispatcher
 
                 if (strpos($exec, '@putenv ') === 0) {
                     putenv(substr($exec, 8));
+                    list($var, $value) = explode('=', substr($exec, 8), 2);
+                    $_SERVER[$var] = $value;
 
                     continue;
                 }
diff --git a/src/Composer/Util/Git.php b/src/Composer/Util/Git.php
index 434a9e0d5..653969305 100644
--- a/src/Composer/Util/Git.php
+++ b/src/Composer/Util/Git.php
@@ -354,7 +354,7 @@ class Git
         // added in git 1.7.1, prevents prompting the user for username/password
         if (getenv('GIT_ASKPASS') !== 'echo') {
             putenv('GIT_ASKPASS=echo');
-            unset($_SERVER['GIT_ASKPASS']);
+            $_SERVER['GIT_ASKPASS'] = 'echo';
         }
 
         // clean up rogue git env vars in case this is running in a git hook
@@ -370,6 +370,7 @@ class Git
         // Run processes with predictable LANGUAGE
         if (getenv('LANGUAGE') !== 'C') {
             putenv('LANGUAGE=C');
+            $_SERVER['LANGUAGE'] = 'C';
         }
 
         // clean up env for OSX, see https://github.com/composer/composer/issues/2146#issuecomment-35478940