diff --git a/src/members-payments.scm b/src/members-payments.scm
index e6e7e2f..c803da8 100644
--- a/src/members-payments.scm
+++ b/src/members-payments.scm
@@ -89,7 +89,7 @@
 				   msg))
 			  (ci3 (substring-index "NULL" msg))
 			  (vs3 (if ci3
-				   (substring msg (+ ci3 4) 4)
+				   (substring msg (+ ci3 4) (+ ci3 4 4))
 				   msg)))
 		     (or (string->number vs1)
 			 (string->number vs2)