diff --git a/src/backend/utils/adt/formatting.c b/src/backend/utils/adt/formatting.c
index d6721f067b1..c5e25d942ec 100644
--- a/src/backend/utils/adt/formatting.c
+++ b/src/backend/utils/adt/formatting.c
@@ -1104,6 +1104,7 @@ NUMDesc_prepare(NUMDesc *num, FormatNode *n)
 			case NUM_D:
 				num->flag |= NUM_F_LDECIMAL;
 				num->need_locale = TRUE;
+				/* FALLTHROUGH */
 			case NUM_DEC:
 				if (IS_DECIMAL(num))
 					ereport(ERROR,