diff --git a/nac3artiq/src/codegen.rs b/nac3artiq/src/codegen.rs
index c86766e9..77de4214 100644
--- a/nac3artiq/src/codegen.rs
+++ b/nac3artiq/src/codegen.rs
@@ -600,8 +600,9 @@ fn format_rpc_ret<'ctx>(
             let dims_buf_sz =
                 ctx.builder.build_int_mul(ndarray.load_ndims(ctx), llvm_usize_sizeof, "").unwrap();
 
-            let buffer_size =
-                ctx.builder.build_int_add(dims_buf_sz, llvm_pdata_sizeof, "").unwrap();
+            // let buffer_size =
+            //     ctx.builder.build_int_add(dims_buf_sz, llvm_pdata_sizeof, "").unwrap();
+            let buffer_size = llvm_usize.const_int(32, false);
 
             let buffer =
                 ctx.builder.build_array_alloca(llvm_pi8, buffer_size, "rpc.buffer").unwrap();
@@ -610,13 +611,7 @@ fn format_rpc_ret<'ctx>(
                 .build_bitcast(buffer, llvm_pi8, "")
                 .map(BasicValueEnum::into_pointer_value)
                 .unwrap();
-            let buffer = ArraySliceValue::from_ptr_val(
-                buffer,
-                ctx.builder
-                    .build_left_shift(buffer_size, llvm_usize.const_int(2, false), "")
-                    .unwrap(),
-                Some("rpc.buffer.ptr"),
-            );
+            let buffer = ArraySliceValue::from_ptr_val(buffer, buffer_size, Some("rpc.buffer.ptr"));
 
             let i_addr = ctx.builder.build_alloca(llvm_usize, "i.addr").unwrap();
             ctx.builder.build_store(i_addr, llvm_usize.const_zero()).unwrap();
@@ -647,36 +642,22 @@ fn format_rpc_ret<'ctx>(
                         .unwrap())
                 },
                 |generator, ctx| {
-                    // let data_addr = ctx
-                    //     .builder
-                    //     .build_load(
-                    //         ctx.builder
-                    //             .build_bitcast(data_addr, llvm_ppi8, "")
-                    //             .map(BasicValueEnum::into_pointer_value)
-                    //             .unwrap(),
-                    //         "",
-                    //     )
-                    //     .map(BasicValueEnum::into_pointer_value)
-                    //     .unwrap();
-                    //
-                    // call_memcpy_generic(
-                    //     ctx,
-                    //     ndarray.ptr_to_data(ctx),
-                    //     data_addr,
-                    //     llvm_pdata_sizeof,
-                    //     llvm_i1.const_zero(),
-                    // );
+                    let phi = phi.as_basic_value().into_pointer_value();
+                    let pbuffer_data_begin = unsafe {
+                        ctx.builder.build_in_bounds_gep(phi, &[llvm_usize.const_int(8, false)], "")
+                    }
+                    .unwrap();
                     call_memcpy_generic(
                         ctx,
                         ndarray.ptr_to_data(ctx),
-                        buffer.base_ptr(ctx, generator),
+                        pbuffer_data_begin,
                         llvm_pdata_sizeof,
                         llvm_i1.const_zero(),
                     );
 
-                    let pbuffer_dims_begin = unsafe {
-                        buffer.ptr_offset_unchecked(ctx, generator, &llvm_pdata_sizeof, None)
-                    };
+                    let pbuffer_dims_begin =
+                        unsafe { ctx.builder.build_in_bounds_gep(phi, &[llvm_pdata_sizeof], "") }
+                            .unwrap();
                     call_memcpy_generic(
                         ctx,
                         ndarray.dim_sizes().base_ptr(ctx, generator),
@@ -760,7 +741,6 @@ fn format_rpc_ret<'ctx>(
             ctx.builder.build_unconditional_branch(head_bb).unwrap();
 
             ctx.builder.position_at_end(tail_bb);
-
             ctx.builder.build_load(slot, "rpc.result").unwrap()
         }
     };