diff --git a/phpBB/docs/CHANGELOG.html b/phpBB/docs/CHANGELOG.html
index 5895920525..3646b82a0b 100644
--- a/phpBB/docs/CHANGELOG.html
+++ b/phpBB/docs/CHANGELOG.html
@@ -230,6 +230,8 @@ p a {
 		<li>[Feature] The converter no longer relies on the smiley ID to decide if it should be displayed on the posting page</li>
 		<li>Limit maximum number of allowed characters in messages to 60.000 by default. Admins should increase their PHP time limits if they want to raise this tremedously.</li>
 		<li>Some changes to the conversion documentation</li>
+		<li>[Fix] Only use permissions from existing forums during the conversion (Bug #11417)</li>
+
 	</ul>
 
 	</div>
diff --git a/phpBB/install/convertors/functions_phpbb20.php b/phpBB/install/convertors/functions_phpbb20.php
index 4346c6f4d1..5db255f7f5 100644
--- a/phpBB/install/convertors/functions_phpbb20.php
+++ b/phpBB/install/convertors/functions_phpbb20.php
@@ -581,10 +581,11 @@ function phpbb_convert_authentication($mode)
 	}
 	// Grab user auth information from 2.0.x board
 	$sql = "SELECT ug.user_id, aa.*
-		FROM {$convert->src_table_prefix}auth_access aa, {$convert->src_table_prefix}user_group ug, {$convert->src_table_prefix}groups g
+		FROM {$convert->src_table_prefix}auth_access aa, {$convert->src_table_prefix}user_group ug, {$convert->src_table_prefix}groups g, {$convert->src_table_prefix}forums f
 		WHERE g.group_id = aa.group_id
 			AND g.group_single_user = 1
-			AND ug.group_id = g.group_id";
+			AND ug.group_id = g.group_id
+			AND f.forum_id = aa.forum_id";
 	$result = $src_db->sql_query($sql);
 
 	$user_access = array();