diff --git a/CHANGES b/CHANGES
index ea87ecbe07..2245e8ce94 100644
--- a/CHANGES
+++ b/CHANGES
@@ -1,3 +1,6 @@
+3430.	[bug]		win32: isc_time_formatISO8601 was missing the
+			'T' between the date and time. [RT #32044]
+
 3429.	[bug]		dns_zone_getserial2 could a return success without
 			returning a valid serial. [RT #32007]
 
diff --git a/bin/tests/names/t_names.c b/bin/tests/names/t_names.c
index 5271d8929f..a0b3f89de1 100644
--- a/bin/tests/names/t_names.c
+++ b/bin/tests/names/t_names.c
@@ -2194,7 +2194,8 @@ static const char *a52 =
 
 static int
 test_dns_name_towire(char *testname, unsigned int dc_method, char *exp_data,
-		     int exp_data_len, isc_result_t exp_result, size_t buflen)
+		     size_t exp_data_len, isc_result_t exp_result,
+		     size_t buflen)
 {
 	int			result;
 	int			val;
@@ -2263,6 +2264,7 @@ t_dns_name_towire_x(const char *testfile, size_t buflen) {
 	int		result;
 	unsigned int	dc_method;
 	isc_result_t	exp_result;
+	size_t		exp_data_len;
 	char		*p;
 	FILE		*fp;
 
@@ -2292,11 +2294,12 @@ t_dns_name_towire_x(const char *testfile, size_t buflen) {
 
 				dc_method = t_dc_method_fromtext(Tokens[3]);
 				exp_result = t_dns_result_fromtext(Tokens[4]);
+				exp_data_len = strtoul(Tokens[3], NULL, 10);
 
 				result = test_dns_name_towire(Tokens[0],
 							      dc_method,
 							      Tokens[2],
-							      atoi(Tokens[3]),
+							      exp_data_len,
 							      exp_result,
 							      buflen);
 			} else {
diff --git a/lib/isc/win32/time.c b/lib/isc/win32/time.c
index fe303f3732..8aaf6bc65f 100644
--- a/lib/isc/win32/time.c
+++ b/lib/isc/win32/time.c
@@ -313,7 +313,7 @@ isc_time_formatISO8601(const isc_time_t *t, char *buf, unsigned int len) {
 		GetTimeFormat(LOCALE_NEUTRAL,
 			      TIME_NOTIMEMARKER | TIME_FORCE24HOURFORMAT,
 			      &st, "hh':'mm':'ss", TimeBuf, 50);
-		snprintf(buf, len, "%s%sZ", DateBuf, TimeBuf);
+		snprintf(buf, len, "%sT%sZ", DateBuf, TimeBuf);
 	} else {
 		buf[0] = 0;
 	}