diff --git a/nac3artiq/src/codegen.rs b/nac3artiq/src/codegen.rs
index b9ef9730..ee7f39dd 100644
--- a/nac3artiq/src/codegen.rs
+++ b/nac3artiq/src/codegen.rs
@@ -24,6 +24,7 @@ use pyo3::{
 
 use crate::{symbol_resolver::InnerResolver, timeline::TimeFns};
 
+use inkwell::values::PointerValue;
 use itertools::Itertools;
 use nac3core::codegen::classes::{ListValue, NDArrayValue, RangeValue, UntypedArrayLikeAccessor};
 use nac3core::codegen::expr::destructure_range;
@@ -763,7 +764,11 @@ fn polymorphic_print<'ctx>(
         let fmt = ctx.gen_string(generator, fmt);
 
         ctx.builder
-            .build_call(print_fn, &once(fmt).chain(args).map(|arg| arg.into()).collect_vec(), "")
+            .build_call(
+                print_fn,
+                &once(fmt).chain(args).map(BasicValueEnum::into).collect_vec(),
+                "",
+            )
             .unwrap();
     };
 
@@ -1081,7 +1086,7 @@ pub fn call_core_log_impl<'ctx>(
 ) -> Result<(), String> {
     let (arg_ty, arg_val) = arg;
 
-    polymorphic_print(ctx, generator, &[(arg_ty, arg_val.into())], "", None, false, false);
+    polymorphic_print(ctx, generator, &[(arg_ty, arg_val.into())], "", None, false, false)?;
 
     Ok(())
 }
@@ -1090,15 +1095,26 @@ pub fn call_core_log_impl<'ctx>(
 pub fn call_rtio_log_impl<'ctx>(
     ctx: &mut CodeGenContext<'ctx, '_>,
     generator: &mut dyn CodeGenerator,
+    channel: PointerValue<'ctx>,
     arg: (Type, BasicValueEnum<'ctx>),
 ) -> Result<(), String> {
     let (arg_ty, arg_val) = arg;
 
-    polymorphic_print(ctx, generator, &[(arg_ty, arg_val.into())], "", None, false, true);
+    polymorphic_print(
+        ctx,
+        generator,
+        &[(ctx.primitives.str, channel.into())],
+        " ",
+        Some("\x1E"),
+        false,
+        true,
+    )?;
+    polymorphic_print(ctx, generator, &[(arg_ty, arg_val.into())], " ", Some("\x1D"), false, true)?;
 
     Ok(())
 }
 
+/// Generates a call to `core_log`.
 pub fn gen_core_log<'ctx>(
     ctx: &mut CodeGenContext<'ctx, '_>,
     obj: &Option<(Type, ValueEnum<'ctx>)>,
@@ -1115,6 +1131,7 @@ pub fn gen_core_log<'ctx>(
     call_core_log_impl(ctx, generator, (value_ty, value_arg))
 }
 
+/// Generates a call to `rtio_log`.
 pub fn gen_rtio_log<'ctx>(
     ctx: &mut CodeGenContext<'ctx, '_>,
     obj: &Option<(Type, ValueEnum<'ctx>)>,
@@ -1125,8 +1142,12 @@ pub fn gen_rtio_log<'ctx>(
     assert!(obj.is_none());
     assert_eq!(args.len(), 1);
 
-    let value_ty = fun.0.args[0].ty;
-    let value_arg = args[0].1.clone().to_basic_value_enum(ctx, generator, value_ty)?;
+    let channel_ty = fun.0.args[0].ty;
+    assert!(ctx.unifier.unioned(channel_ty, ctx.primitives.str));
+    let channel_arg =
+        args[0].1.clone().to_basic_value_enum(ctx, generator, channel_ty)?.into_pointer_value();
+    let value_ty = fun.0.args[1].ty;
+    let value_arg = args[1].1.clone().to_basic_value_enum(ctx, generator, value_ty)?;
 
-    call_rtio_log_impl(ctx, generator, (value_ty, value_arg))
+    call_rtio_log_impl(ctx, generator, channel_arg, (value_ty, value_arg))
 }
diff --git a/nac3artiq/src/lib.rs b/nac3artiq/src/lib.rs
index db2c3a6e..3b4df2e1 100644
--- a/nac3artiq/src/lib.rs
+++ b/nac3artiq/src/lib.rs
@@ -909,7 +909,7 @@ impl Nac3 {
                     "core_log".into(),
                     FunSignature {
                         args: vec![FuncArg {
-                            name: "obj".into(),
+                            name: "arg".into(),
                             ty: arg_ty.ty,
                             default_value: None,
                             is_vararg: false,
@@ -930,12 +930,20 @@ impl Nac3 {
                 (
                     "rtio_log".into(),
                     FunSignature {
-                        args: vec![FuncArg {
-                            name: "obj".into(),
-                            ty: arg_ty.ty,
-                            default_value: None,
-                            is_vararg: false,
-                        }],
+                        args: vec![
+                            FuncArg {
+                                name: "channel".into(),
+                                ty: primitive.str,
+                                default_value: None,
+                                is_vararg: false,
+                            },
+                            FuncArg {
+                                name: "arg".into(),
+                                ty: arg_ty.ty,
+                                default_value: None,
+                                is_vararg: false,
+                            },
+                        ],
                         ret: primitive.none,
                         vars: into_var_map([arg_ty]),
                     },