diff --git a/src/backend/utils/adt/varlena.c b/src/backend/utils/adt/varlena.c
index 693ccc5149..366a49665a 100644
--- a/src/backend/utils/adt/varlena.c
+++ b/src/backend/utils/adt/varlena.c
@@ -1835,7 +1835,7 @@ text_starts_with(PG_FUNCTION_ARGS)
 		result = false;
 	else
 	{
-		text	   *targ1 = DatumGetTextPP(arg1);
+		text	   *targ1 = text_substring(arg1, 1, len2, false);
 		text	   *targ2 = DatumGetTextPP(arg2);
 
 		result = (memcmp(VARDATA_ANY(targ1), VARDATA_ANY(targ2),
@@ -5237,17 +5237,22 @@ text_concat_ws(PG_FUNCTION_ARGS)
 Datum
 text_left(PG_FUNCTION_ARGS)
 {
-	text	   *str = PG_GETARG_TEXT_PP(0);
-	const char *p = VARDATA_ANY(str);
-	int			len = VARSIZE_ANY_EXHDR(str);
-	int			n = PG_GETARG_INT32(1);
-	int			rlen;
+	int		n = PG_GETARG_INT32(1);
 
 	if (n < 0)
+	{
+		text	   *str = PG_GETARG_TEXT_PP(0);
+		const char *p = VARDATA_ANY(str);
+		int			len = VARSIZE_ANY_EXHDR(str);
+		int			rlen;
 		n = pg_mbstrlen_with_len(p, len) + n;
-	rlen = pg_mbcharcliplen(p, len, n);
-
-	PG_RETURN_TEXT_P(cstring_to_text_with_len(p, rlen));
+		rlen = pg_mbcharcliplen(p, len, n);
+		PG_RETURN_TEXT_P(cstring_to_text_with_len(p, rlen));
+	}
+	else
+	{
+		PG_RETURN_TEXT_P(text_substring(PG_GETARG_DATUM(0), 1, n, false));
+	}
 }
 
 /*