diff --git a/binding_generator.py b/binding_generator.py
index af26d3e4b..dc6e66274 100644
--- a/binding_generator.py
+++ b/binding_generator.py
@@ -802,6 +802,10 @@ def generate_builtin_class_header(builtin_api, size, used_classes, fully_used_cl
     # We don't get alignment information from the JSON so we have to guess.
     # This logic should be correct for all built-in types as they exist right now.
     alignment = 8 if size >= 8 else 4
+    if class_name == "RID":
+        alignment = "uint64_t"
+    elif is_packed_array(class_name):
+        alignment = "void *"
     result.append(f"\talignas({alignment}) uint8_t opaque[{snake_class_name}_SIZE] = {{}};")
 
     result.append("")