diff --git a/nac3artiq/src/codegen.rs b/nac3artiq/src/codegen.rs
index 83fa247c..79802867 100644
--- a/nac3artiq/src/codegen.rs
+++ b/nac3artiq/src/codegen.rs
@@ -581,23 +581,38 @@ fn rpc_codegen_callback_fn<'ctx>(
             let buffer = ctx.builder.build_array_alloca(int8, buffer_size, "").unwrap();
             let buffer = ArraySliceValue::from_ptr_val(buffer, buffer_size, None);
 
-            llvm_intrinsics::call_memcpy_generic(
-                ctx,
-                buffer.base_ptr(ctx, generator),
-                llvm_arg.dim_sizes().base_ptr(ctx, generator),
-                dims_buf_sz,
-                int1.const_zero(),
-            );
+            for (offset, byte) in
+                [0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 1u8].into_iter().enumerate()
+            {
+                let pbuffer = unsafe {
+                    buffer.ptr_offset_unchecked(
+                        ctx,
+                        generator,
+                        &size_type.const_int(offset as u64, false),
+                        None,
+                    )
+                };
 
-            let pbuffer_data_begin =
-                unsafe { buffer.ptr_offset_unchecked(ctx, generator, &dims_buf_sz, None) };
-            llvm_intrinsics::call_memcpy_generic(
-                ctx,
-                pbuffer_data_begin,
-                llvm_arg.data().base_ptr(ctx, generator),
-                data_buf_sz,
-                int1.const_zero(),
-            );
+                ctx.builder.build_store(pbuffer, int8.const_int(byte as u64, false)).unwrap();
+            }
+
+            // llvm_intrinsics::call_memcpy_generic(
+            //     ctx,
+            //     buffer.base_ptr(ctx, generator),
+            //     llvm_arg.dim_sizes().base_ptr(ctx, generator),
+            //     dims_buf_sz,
+            //     int1.const_zero(),
+            // );
+            //
+            // let pbuffer_data_begin =
+            //     unsafe { buffer.ptr_offset_unchecked(ctx, generator, &dims_buf_sz, None) };
+            // llvm_intrinsics::call_memcpy_generic(
+            //     ctx,
+            //     pbuffer_data_begin,
+            //     llvm_arg.data().base_ptr(ctx, generator),
+            //     data_buf_sz,
+            //     int1.const_zero(),
+            // );
 
             buffer.base_ptr(ctx, generator)
         } else {