diff --git a/contrib/pg_upgrade/check.c b/contrib/pg_upgrade/check.c
new file mode 100644
index 2117b7f..60c1fbb
*** a/contrib/pg_upgrade/check.c
--- b/contrib/pg_upgrade/check.c
*************** static void
*** 333,345 ****
  check_locale_and_encoding(ControlData *oldctrl,
  						  ControlData *newctrl)
  {
! 	if (strcmp(oldctrl->lc_collate, newctrl->lc_collate) != 0)
  		pg_log(PG_FATAL,
  			   "old and new cluster lc_collate values do not match\n");
! 	if (strcmp(oldctrl->lc_ctype, newctrl->lc_ctype) != 0)
  		pg_log(PG_FATAL,
  			   "old and new cluster lc_ctype values do not match\n");
! 	if (strcmp(oldctrl->encoding, newctrl->encoding) != 0)
  		pg_log(PG_FATAL,
  			   "old and new cluster encoding values do not match\n");
  }
--- 333,346 ----
  check_locale_and_encoding(ControlData *oldctrl,
  						  ControlData *newctrl)
  {
! 	/* These are often defined with inconsistent case, so use pg_strcasecmp(). */
! 	if (pg_strcasecmp(oldctrl->lc_collate, newctrl->lc_collate) != 0)
  		pg_log(PG_FATAL,
  			   "old and new cluster lc_collate values do not match\n");
! 	if (pg_strcasecmp(oldctrl->lc_ctype, newctrl->lc_ctype) != 0)
  		pg_log(PG_FATAL,
  			   "old and new cluster lc_ctype values do not match\n");
! 	if (pg_strcasecmp(oldctrl->encoding, newctrl->encoding) != 0)
  		pg_log(PG_FATAL,
  			   "old and new cluster encoding values do not match\n");
  }