diff --git a/classes/PlagScan/DocumentManagement.php b/classes/PlagScan/DocumentManagement.php
index d2b40bcdca9d97c53ae0a9938d13d7dcf7b64f6b..8e203e9a780fa1d7279fdeceed4079a86ae868ff 100644
--- a/classes/PlagScan/DocumentManagement.php
+++ b/classes/PlagScan/DocumentManagement.php
@@ -114,7 +114,7 @@ class DocumentManagement
         global $DIC;
 
         $result = $DIC->database()->queryF(
-            'SELECT * FROM psx_submissions WHERE plagscan_status = ',
+            'SELECT * FROM psx_submissions WHERE plagscan_status = %s',
             [ilDBConstants::T_TEXT],
             ['not_checked']
         );