diff --git a/tests/mpz/t-scan.c b/tests/mpz/t-scan.c
index a52c011d..7bcd26d3 100644
--- a/tests/mpz/t-scan.c
+++ b/tests/mpz/t-scan.c
@@ -84,7 +84,7 @@ check_ref (void)
 
               for (isize = 0; isize <= size; isize++)
                 {
-                  for (oindex = 0; oindex <= numberof (offset); oindex++)
+                  for (oindex = 0; oindex < numberof (offset); oindex++)
                     {
                       o = offset[oindex];
                       if ((int) isize*GMP_NUMB_BITS < -o)