diff --git a/src/shk.c b/src/shk.c
index 6cf62f2c0..addf8aac7 100644
--- a/src/shk.c
+++ b/src/shk.c
@@ -859,7 +859,7 @@ boolean silent;
             } else
                 bp++;
     }
-    if (obj->unpaid & !silent)
+    if (obj->unpaid && !silent)
         pline("onbill: unpaid obj not on bill?");
     return (struct bill_x *) 0;
 }