diff --git a/src/ptrace/_UPT_access_fpreg.c b/src/ptrace/_UPT_access_fpreg.c
index 283dcd4f..40143775 100644
--- a/src/ptrace/_UPT_access_fpreg.c
+++ b/src/ptrace/_UPT_access_fpreg.c
@@ -36,7 +36,7 @@ _UPT_access_fpreg (unw_addr_space_t as, unw_regnum_t reg, unw_fpreg_t *val,
   pid_t pid = ui->pid;
   int i;
 
-  if ((unsigned) reg >= sizeof (_UPT_reg_offset) / sizeof (_UPT_reg_offset[0]))
+  if ((unsigned) reg >= ARRAY_SIZE (_UPT_reg_offset))
     return -UNW_EBADREG;
 
   errno = 0;
@@ -75,7 +75,7 @@ _UPT_access_fpreg (unw_addr_space_t as, unw_regnum_t reg, unw_fpreg_t *val,
   pid_t pid = ui->pid;
   fpregset_t fpreg;
 
-  if ((unsigned) reg >= sizeof (_UPT_reg_offset) / sizeof (_UPT_reg_offset[0]))
+  if ((unsigned) reg >= ARRAY_SIZE (_UPT_reg_offset))
     return -UNW_EBADREG;
 
   if (ptrace(PT_GETFPREGS, pid, (caddr_t)&fpreg, 0) == -1)
diff --git a/src/ptrace/_UPT_access_reg.c b/src/ptrace/_UPT_access_reg.c
index ed259d82..782eeb70 100644
--- a/src/ptrace/_UPT_access_reg.c
+++ b/src/ptrace/_UPT_access_reg.c
@@ -225,7 +225,7 @@ _UPT_access_reg (unw_addr_space_t as, unw_regnum_t reg, unw_word_t *val,
       }
 #endif /* End of IA64 */
 
-  if ((unsigned) reg >= sizeof (_UPT_reg_offset) / sizeof (_UPT_reg_offset[0]))
+  if ((unsigned) reg >= ARRAY_SIZE (_UPT_reg_offset))
     {
 #if UNW_DEBUG
       Debug(2, "register out of range: >= %zu / %zu\n", sizeof(_UPT_reg_offset), sizeof(_UPT_reg_offset[0]));
@@ -284,7 +284,7 @@ _UPT_access_reg (unw_addr_space_t as, unw_regnum_t reg, unw_word_t *val,
   if (write)
     Debug (16, "%s [%u] <- %lx\n", unw_regname (reg), (unsigned) reg, (long) *val);
 #endif
-  if ((unsigned) reg >= sizeof (_UPT_reg_offset) / sizeof (_UPT_reg_offset[0]))
+  if ((unsigned) reg >= ARRAY_SIZE (_UPT_reg_offset))
     {
       errno = EINVAL;
       goto badreg;