diff --git a/vpi/fstapi.c b/vpi/fstapi.c
index ed818bfb8..9845edacd 100644
--- a/vpi/fstapi.c
+++ b/vpi/fstapi.c
@@ -3910,7 +3910,7 @@ char *pnt = buf;
  int len = 0;
 
 /* zero is illegal for a value...it is assumed they start at one */
-while (value && len <= 14)
+while (value && len < 14)
         {
         value--;
 	++len;