diff --git a/ext/standard/pack.c b/ext/standard/pack.c
index 969f5a2db742..3c6bb7c35e2f 100644
--- a/ext/standard/pack.c
+++ b/ext/standard/pack.c
@@ -1260,7 +1260,7 @@ PHP_FUNCTION(unpack)
 						if (type == 'l') {
 							v = (int32_t) x;
 						} else {
-							v = x;
+							v = (zend_long) x;
 						}
 
 						ZVAL_LONG(&val, v);