2 files changed, 10 insertions, 5 deletions

diff --git a/embassy-usb/src/msos.rs b/embassy-usb/src/msos.rs
index 66689871e..6d7f87061 100644
--- a/embassy-usb/src/msos.rs
+++ b/embassy-usb/src/msos.rs
@@ -110,10 +110,6 @@ impl<'d> MsOsDescriptorWriter<'d> {
             !self.is_empty(),
             "device features may only be added after the header is written"
         );
-        assert!(
-            self.config_mark.is_none(),
-            "device features must be added before the first configuration subset"
-        );
         self.write(desc);
     }
 
diff --git a/examples/rp/src/bin/usb_webusb.rs b/examples/rp/src/bin/usb_webusb.rs
index 5cecb92f0..edc9a0c52 100644
--- a/examples/rp/src/bin/usb_webusb.rs
+++ b/examples/rp/src/bin/usb_webusb.rs
@@ -26,6 +26,7 @@ use embassy_rp::usb::{Driver as UsbDriver, InterruptHandler};
 use embassy_usb::class::web_usb::{Config as WebUsbConfig, State, Url, WebUsb};
 use embassy_usb::driver::{Driver, Endpoint, EndpointIn, EndpointOut};
 use embassy_usb::msos::{self, windows_version};
+use embassy_usb::types::InterfaceNumber;
 use embassy_usb::{Builder, Config};
 use {defmt_rtt as _, panic_probe as _};
 
@@ -56,7 +57,7 @@ async fn main(_spawner: Spawner) {
     let mut config_descriptor = [0; 256];
     let mut bos_descriptor = [0; 256];
     let mut control_buf = [0; 64];
-    let mut msos_descriptor = [0; 256];
+    let mut msos_descriptor = [0; 512];
 
     let webusb_config = WebUsbConfig {
         max_packet_size: 64,
@@ -83,6 +84,14 @@ async fn main(_spawner: Spawner) {
     // In principle you might want to call msos_feature() just on a specific function,
     // if your device also has other functions that still use standard class drivers.
     builder.msos_descriptor(windows_version::WIN8_1, 0);
+    builder.msos_writer().configuration(0);
+    builder.msos_writer().function(InterfaceNumber(0));
+    builder.msos_feature(msos::CompatibleIdFeatureDescriptor::new("WINUSB", ""));
+    builder.msos_feature(msos::RegistryPropertyFeatureDescriptor::new(
+        "DeviceInterfaceGUIDs",
+        msos::PropertyData::RegMultiSz(DEVICE_INTERFACE_GUIDS),
+    ));
+    builder.msos_writer().function(InterfaceNumber(1));
     builder.msos_feature(msos::CompatibleIdFeatureDescriptor::new("WINUSB", ""));
     builder.msos_feature(msos::RegistryPropertyFeatureDescriptor::new(
         "DeviceInterfaceGUIDs",