diff --git a/NEWS b/NEWS
index 48afd654b2ef..b1252555b41f 100644
--- a/NEWS
+++ b/NEWS
@@ -58,6 +58,8 @@ PHP                                                                        NEWS
 - MySQLnd:
   . Fixed bug GH-24293 (Segfault on connect with an empty password to a
     MariaDB PAM account). (lazerg)
+  . Fixed bug GH-16910 (Fractional seconds truncated in prepared statements
+    if decimals is AUTO_SEC_PART_DIGITS). (Ojus Chugh)
 
 - Opcache:
   . Fixed bug GH-20890 (Segfault in zval_undefined_cv with non-simple property
diff --git a/ext/mysqli/tests/gh16910.phpt b/ext/mysqli/tests/gh16910.phpt
new file mode 100644
index 000000000000..910f586d2f39
--- /dev/null
+++ b/ext/mysqli/tests/gh16910.phpt
@@ -0,0 +1,42 @@
+--TEST--
+GH-16910 (Fractional seconds truncated in prepared statements if decimals is AUTO_SEC_PART_DIGITS)
+--EXTENSIONS--
+mysqli
+--SKIPIF--
+<?php
+require_once 'connect.inc';
+if (!$link = @my_mysqli_connect($host, $user, $passwd, $db, $port, $socket))
+    die(sprintf("SKIP Cannot connect to the server using host=%s, user=%s, passwd=***, dbname=%s, port=%s, socket=%s\n",
+        $host, $user, $db, $port, $socket));
+$stmt = $link->prepare("SELECT FROM_UNIXTIME('1992.1')");
+if (!$stmt || $stmt->result_metadata()->fetch_field_direct(0)->decimals !== 39)
+    die("SKIP Server does not report AUTO_SEC_PART_DIGITS for FROM_UNIXTIME()");
+?>
+--FILE--
+<?php
+require_once 'connect.inc';
+
+mysqli_report(MYSQLI_REPORT_ERROR | MYSQLI_REPORT_STRICT);
+$link = new my_mysqli($host, $user, $passwd, $db, $port, $socket);
+$link->query("SET time_zone = '+00:00'");
+
+$sql = "SELECT FROM_UNIXTIME('1992.1'), FROM_UNIXTIME('1992.0')";
+var_dump($link->query($sql)->fetch_row());
+
+$stmt = $link->prepare($sql);
+$stmt->execute();
+var_dump($stmt->get_result()->fetch_row());
+?>
+--EXPECT--
+array(2) {
+  [0]=>
+  string(26) "1970-01-01 00:33:12.100000"
+  [1]=>
+  string(19) "1970-01-01 00:33:12"
+}
+array(2) {
+  [0]=>
+  string(26) "1970-01-01 00:33:12.100000"
+  [1]=>
+  string(19) "1970-01-01 00:33:12"
+}
diff --git a/ext/mysqlnd/mysqlnd_ps_codec.c b/ext/mysqlnd/mysqlnd_ps_codec.c
index 787fe3b245cd..53ff394ebeb8 100644
--- a/ext/mysqlnd/mysqlnd_ps_codec.c
+++ b/ext/mysqlnd/mysqlnd_ps_codec.c
@@ -305,10 +305,11 @@ ps_fetch_time(zval * zv, const MYSQLND_FIELD * const field, const unsigned int p
 		t.time_type = MYSQLND_TIMESTAMP_TIME;
 	}
 
-	if (field->decimals > 0 && field->decimals < 7) {
+	unsigned int decimals = field->decimals > 6 ? (t.second_part ? 6 : 0) : field->decimals;
+	if (decimals > 0) {
 		ZVAL_STR(zv, zend_strpprintf(0, "%s%02u:%02u:%02u.%0*u",
-			(t.neg ? "-" : ""), t.hour, t.minute, t.second, field->decimals,
-			(uint32_t) (t.second_part / pow(10, 6 - field->decimals))));
+			(t.neg ? "-" : ""), t.hour, t.minute, t.second, decimals,
+			(uint32_t) (t.second_part / pow(10, 6 - decimals))));
 	} else {
 		 ZVAL_STR(zv, zend_strpprintf(0, "%s%02u:%02u:%02u",
 			(t.neg ? "-" : ""), t.hour, t.minute, t.second));
@@ -401,10 +402,11 @@ ps_fetch_datetime(zval * zv, const MYSQLND_FIELD * const field, const unsigned i
 		t.time_type = MYSQLND_TIMESTAMP_DATETIME;
 	}
 
-	if (field->decimals > 0 && field->decimals < 7) {
+	unsigned int decimals = field->decimals > 6 ? (t.second_part ? 6 : 0) : field->decimals;
+	if (decimals > 0) {
 		ZVAL_STR(zv, zend_strpprintf(0, "%04u-%02u-%02u %02u:%02u:%02u.%0*u",
-			t.year, t.month, t.day, t.hour, t.minute, t.second, field->decimals,
-			(uint32_t) (t.second_part / pow(10, 6 - field->decimals))));
+			t.year, t.month, t.day, t.hour, t.minute, t.second, decimals,
+			(uint32_t) (t.second_part / pow(10, 6 - decimals))));
 	} else {
 		ZVAL_STR(zv,  zend_strpprintf(0, "%04u-%02u-%02u %02u:%02u:%02u",
 			t.year, t.month, t.day, t.hour, t.minute, t.second));