diff --git a/ext/session/session.c b/ext/session/session.c
index 5ea341d0bb2..aa9883ab1df 100644
--- a/ext/session/session.c
+++ b/ext/session/session.c
@@ -1875,13 +1875,13 @@ PHP_FUNCTION(session_get_cookie_params)
 }
 /* }}} */
 
-/* {{{ Return the current session name. If newname is given, the session name is replaced with newname */
+/* {{{ Return the current session name. If new name is given, the session name is replaced with new name */
 PHP_FUNCTION(session_name)
 {
 	zend_string *name = NULL;
 	zend_string *ini_name;
 
-	if (zend_parse_parameters(ZEND_NUM_ARGS(), "|S!", &name) == FAILURE) {
+	if (zend_parse_parameters(ZEND_NUM_ARGS(), "|P!", &name) == FAILURE) {
 		RETURN_THROWS();
 	}
 
diff --git a/ext/session/tests/session_name_variation1.phpt b/ext/session/tests/session_name_variation1.phpt
index 07fb7f10ca8..ef68b80b3de 100644
--- a/ext/session/tests/session_name_variation1.phpt
+++ b/ext/session/tests/session_name_variation1.phpt
@@ -15,12 +15,6 @@ ob_start();
 
 echo "*** Testing session_name() : variation ***\n";
 
-var_dump(session_name("\0"));
-var_dump(session_start());
-var_dump(session_name());
-var_dump(session_destroy());
-var_dump(session_name());
-
 var_dump(session_name("\t"));
 var_dump(session_start());
 var_dump(session_name());
@@ -39,11 +33,6 @@ ob_end_flush();
 --EXPECTF--
 *** Testing session_name() : variation ***
 string(9) "PHPSESSID"
-bool(true)
-string(9) "PHPSESSID"
-bool(true)
-string(9) "PHPSESSID"
-string(9) "PHPSESSID"
 
 Warning: session_start(): session.name cannot contain any of the following '=,;.[ \t\r\n\013\014' in %s on line %d
 bool(true)
diff --git a/ext/session/tests/session_name_variation_null_byte.phpt b/ext/session/tests/session_name_variation_null_byte.phpt
new file mode 100644
index 00000000000..84b6ccfb1e6
--- /dev/null
+++ b/ext/session/tests/session_name_variation_null_byte.phpt
@@ -0,0 +1,21 @@
+--TEST--
+Test session_name() function : null byte in session name
+--EXTENSIONS--
+session
+--SKIPIF--
+<?php include('skipif.inc'); ?>
+--FILE--
+<?php
+
+try {
+    var_dump(session_name("AB\0CD"));
+    var_dump(session_start());
+} catch (ValueError $e) {
+    echo $e->getMessage(). "\n";
+}
+
+echo "Done";
+?>
+--EXPECT--
+session_name(): Argument #1 ($name) must not contain any null bytes
+Done