diff --git a/lib/c-api/src/wasm_c_api/types/function.rs b/lib/c-api/src/wasm_c_api/types/function.rs
index 35b845481d6..cf8cfeaa347 100644
--- a/lib/c-api/src/wasm_c_api/types/function.rs
+++ b/lib/c-api/src/wasm_c_api/types/function.rs
@@ -90,7 +90,7 @@ impl wasm_functype_t {
     }
 }
 
-wasm_declare_vec!(functype);
+wasm_declare_boxed_vec!(functype);
 
 #[no_mangle]
 pub unsafe extern "C" fn wasm_functype_new(