diff --git a/ext/standard/tests/serialize/bug69139.phpt b/ext/standard/tests/serialize/bug69139.phpt
new file mode 100644
index 00000000000..48127a2461c
--- /dev/null
+++ b/ext/standard/tests/serialize/bug69139.phpt
@@ -0,0 +1,10 @@
+--TEST--
+Bug #69139 (Crash in gc_zval_possible_root on unserialize)
+--FILE--
+<?php
+$str = 'a:1126666:{i:0;r:1;i:-09610;r:1;i:-0;i:0;i:0;O:1:"A":2119X:i:0;i:0;i:0;i:0;i:0;O:1:"A":2116:{i:0;r:5;i:-096766610;r:1;i:-610;r:1;i:0;i:0;';
+@unserialize($str);
+echo "Alive";
+?>
+--EXPECT--
+Alive
diff --git a/ext/standard/var.c b/ext/standard/var.c
index 5e986d451d3..1c5a000c250 100644
--- a/ext/standard/var.c
+++ b/ext/standard/var.c
@@ -1036,7 +1036,7 @@ PHP_FUNCTION(unserialize)
 			zend_hash_destroy(class_hash);
 			FREE_HASHTABLE(class_hash);
 		}
-		zval_dtor(return_value);
+		zval_ptr_dtor(return_value);
 		if (!EG(exception)) {
 			php_error_docref(NULL, E_NOTICE, "Error at offset " ZEND_LONG_FMT " of %d bytes", (zend_long)((char*)p - buf), buf_len);
 		}