diff --git a/phpBB/language/en/acp/forums.php b/phpBB/language/en/acp/forums.php
index b4f0f060e9..e8c85ae8a8 100644
--- a/phpBB/language/en/acp/forums.php
+++ b/phpBB/language/en/acp/forums.php
@@ -44,6 +44,8 @@ $lang = array_merge($lang, array(
 	'AUTO_PRUNE_FREQ_EXPLAIN'	=> 'Time in days between pruning events.',
 	'AUTO_PRUNE_VIEWED'			=> 'Auto-prune post viewed age',
 	'AUTO_PRUNE_VIEWED_EXPLAIN'	=> 'Number of days since topic was viewed after which topic is removed.',
+	'AUTO_PRUNE_SHADOW_FREQ'	=> 'Auto-prune shadow topics frequency',
+	'AUTO_PRUNE_SHADOW_DAYS'	=> 'Auto-prune shadow topics age',
 
 	'CONTINUE'						=> 'Continue',
 	'COPY_PERMISSIONS'				=> 'Copy permissions from',