diff --git a/src/protocol/mod.rs b/src/protocol/mod.rs
index b87ab6815f6f15684065fb1c3b351579b5e13528..f8152663c94d7478727360046c862f7c0192c0f2 100644
--- a/src/protocol/mod.rs
+++ b/src/protocol/mod.rs
@@ -13,6 +13,7 @@ use crate::protocol::inputsource::*;
 use crate::protocol::parser::*;
 
 #[derive(serde::Serialize, serde::Deserialize)]
+#[repr(C)]
 pub struct ProtocolDescription {
     heap: Heap,
     source: InputSource,