diff --git a/nac3artiq/src/codegen.rs b/nac3artiq/src/codegen.rs
index d70f249a..b25d44dc 100644
--- a/nac3artiq/src/codegen.rs
+++ b/nac3artiq/src/codegen.rs
@@ -566,7 +566,7 @@ fn rpc_codegen_callback_fn<'ctx>(
             let data_buf_sz = ctx
                 .builder
                 .build_int_mul(
-                    call_ndarray_calc_size(generator, ctx, &llvm_arg.data(), (None, None)),
+                    call_ndarray_calc_size(generator, ctx, &llvm_arg.dim_sizes(), (None, None)),
                     llvm_elem_sizeof,
                     "",
                 )