diff --git a/modules/mol/alg/pymod/qsscoring.py b/modules/mol/alg/pymod/qsscoring.py
index 7c7cb3cfe1d8073152c5850ad807c9fa0376a28c..565768efba5255dab786d1003f79e56a31d3ff6b 100644
--- a/modules/mol/alg/pymod/qsscoring.py
+++ b/modules/mol/alg/pymod/qsscoring.py
@@ -606,8 +606,8 @@ class QSscoreEntity(object):
 
   .. attribute:: is_valid
 
-    True, if successfully initialized. False, if input structure is monomer or
-    has less than 2 protein chains with >= 20 residues.
+    True, if successfully initialized. False, if input structure has no protein
+    chains with >= 20 residues.
 
     :type: :class:`bool`