diff --git a/doc/03-cli.md b/doc/03-cli.md
index 5fc527c49..6460e9e1d 100644
--- a/doc/03-cli.md
+++ b/doc/03-cli.md
@@ -917,10 +917,6 @@ if you use Composer as super user at all times like in docker containers.
 
 If set, the value is used as php's memory_limit.
 
-### COMPOSER_SELF_UPDATE_TARGET
-
-If set, makes the self-update command write the new Composer phar file into that path instead of overwriting itself. Useful for updating Composer on read-only filesystem.
-
 ### COMPOSER_MIRROR_PATH_REPOS
 
 If set to 1, this env changes the default path repository strategy to `mirror` instead
diff --git a/src/Composer/Command/SelfUpdateCommand.php b/src/Composer/Command/SelfUpdateCommand.php
index 226aafeb5..78b27460e 100644
--- a/src/Composer/Command/SelfUpdateCommand.php
+++ b/src/Composer/Command/SelfUpdateCommand.php
@@ -351,10 +351,6 @@ TAGSPUBKEY
                 @copy($localFilename, $backupTarget);
             }
 
-            if ($targetFilename = getenv('COMPOSER_SELF_UPDATE_TARGET')) {
-                $localFilename = realpath($targetFilename) ?: $targetFilename;
-            }
-
             rename($newFilename, $localFilename);
 
             return null;