diff --git a/examples/std/src/tuntap.rs b/examples/std/src/tuntap.rs
index 53d3afd5c..a32099404 100644
--- a/examples/std/src/tuntap.rs
+++ b/examples/std/src/tuntap.rs
@@ -50,7 +50,6 @@ fn ifreq_ioctl(
 #[derive(Debug)]
 pub struct TunTap {
     fd: libc::c_int,
-    ifreq: ifreq,
     mtu: usize,
 }
 
@@ -88,7 +87,7 @@ impl TunTap {
             // smoltcp counts the entire Ethernet packet in the MTU, so add the Ethernet header size to it.
             let mtu = ip_mtu + EthernetFrame::<&[u8]>::header_len();
 
-            Ok(TunTap { fd, mtu, ifreq })
+            Ok(TunTap { fd, mtu })
         }
     }
 }
diff --git a/rust-toolchain.toml b/rust-toolchain.toml
index 00901f820..d45871808 100644
--- a/rust-toolchain.toml
+++ b/rust-toolchain.toml
@@ -1,6 +1,6 @@
 # Before upgrading check that everything is available on all tier1 targets here:
 # https://rust-lang.github.io/rustup-components-history
 [toolchain]
-channel = "nightly-2021-08-18"
+channel = "nightly-2021-10-16"
 components = [ "rust-src", "rustfmt" ]
 targets = [ "thumbv7em-none-eabi", "thumbv7m-none-eabi", "thumbv6m-none-eabi", "thumbv7em-none-eabihf", "thumbv8m.main-none-eabihf", "wasm32-unknown-unknown" ]