diff --git a/libraries/liblunicode/ure/ure.c b/libraries/liblunicode/ure/ure.c
index ffbd9b5e2c..195289f48d 100644
--- a/libraries/liblunicode/ure/ure.c
+++ b/libraries/liblunicode/ure/ure.c
@@ -416,7 +416,7 @@ _ure_prop_list(ucs2_t *pp, unsigned long limit, unsigned long *mask,
           b->error = _URE_INVALID_PROPERTY;
     }
 
-    if (n != 0)
+    if (b->error == _URE_OK && n != 0)
       m |= cclass_flags[n];
 
     /*