diff --git a/vfio_user/src/lib.rs b/vfio_user/src/lib.rs
index 3c0779099..5093902ff 100644
--- a/vfio_user/src/lib.rs
+++ b/vfio_user/src/lib.rs
@@ -272,6 +272,8 @@ pub enum Error {
     SocketAccept(#[source] std::io::Error),
     #[error("Unsupported command: {0:?}")]
     UnsupportedCommand(Command),
+    #[error("Unsupported feature")]
+    UnsupportedFeature,
     #[error("Error from backend: {0:?}")]
     Backend(#[source] std::io::Error),
 }
@@ -1084,6 +1086,10 @@ impl Server {
                     .read_exact(&mut cmd.as_mut_slice()[size_of::<Header>()..])
                     .map_err(Error::StreamRead)?;
 
+                if cmd.flags & VFIO_IRQ_SET_DATA_BOOL > 0 {
+                    return Err(Error::UnsupportedFeature);
+                }
+
                 backend
                     .set_irqs(cmd.index, cmd.flags, cmd.start, cmd.count, fds)
                     .map_err(Error::Backend)?;