diff --git a/Zend/zend_gc.h b/Zend/zend_gc.h
index 262d656c24ea8..06f550647bd79 100644
--- a/Zend/zend_gc.h
+++ b/Zend/zend_gc.h
@@ -134,6 +134,8 @@ static zend_always_inline void zend_get_gc_buffer_add_zval(
 
 static zend_always_inline void zend_get_gc_buffer_add_obj(
 		zend_get_gc_buffer *gc_buffer, zend_object *obj) {
+	ZEND_ASSERT(obj != NULL);
+
 	if (UNEXPECTED(gc_buffer->cur == gc_buffer->end)) {
 		zend_get_gc_buffer_grow(gc_buffer);
 	}