diff --git a/src/wrapper/standalone/backend/cpal.rs b/src/wrapper/standalone/backend/cpal.rs
index 86e4abcd..44c7db48 100644
--- a/src/wrapper/standalone/backend/cpal.rs
+++ b/src/wrapper/standalone/backend/cpal.rs
@@ -284,6 +284,15 @@ impl Cpal {
             nih_log!("Audio-only, MIDI input and output has not been implemented yet.");
         }
 
+        // There's no obvious way to do sidechain inputs and additional outputs with the CPAL
+        // backends like there is with JACK. So we'll just provide empty buffers instead.
+        if !audio_io_layout.aux_input_ports.is_empty() {
+            nih_warn!("Sidechain inputs are not supported with this audio backend");
+        }
+        if !audio_io_layout.aux_output_ports.is_empty() {
+            nih_warn!("Auxiliary outputs are not supported with this audio backend");
+        }
+
         Ok(Cpal {
             config,
             audio_io_layout,
diff --git a/src/wrapper/standalone/wrapper.rs b/src/wrapper/standalone/wrapper.rs
index 760f459f..3adefec0 100644
--- a/src/wrapper/standalone/wrapper.rs
+++ b/src/wrapper/standalone/wrapper.rs
@@ -212,14 +212,6 @@ impl<P: Plugin, B: Backend<P>> Wrapper<P, B> {
             }
         }
 
-        // TODO: Sidechain inputs and auxiliary outputs
-        if !audio_io_layout.aux_input_ports.is_empty() {
-            nih_warn!("Sidechain inputs are not yet supported in this standalone version");
-        }
-        if !audio_io_layout.aux_output_ports.is_empty() {
-            nih_warn!("Auxiliary outputs are not yet supported in this standalone version");
-        }
-
         let wrapper = Arc::new(Wrapper {
             backend: AtomicRefCell::new(backend),