diff --git a/src/iface/ethernet.rs b/src/iface/ethernet.rs
index 0a0d13e..1be01c7 100644
--- a/src/iface/ethernet.rs
+++ b/src/iface/ethernet.rs
@@ -1026,12 +1026,9 @@ impl<'b, 'c, 'e> InterfaceInner<'b, 'c, 'e> {
            !self.has_multicast_group(ipv4_repr.dst_addr) {
             // Ignore IP packets not directed at us, or broadcast, or any of the multicast groups.
             // If AnyIP is enabled, also check if the packet is routed locally.
-            if !self.any_ip {
-                return Ok(None);
-            } else if match self.routes.lookup(&IpAddress::Ipv4(ipv4_repr.dst_addr), timestamp) {
-                Some(router_addr) => !self.has_ip_addr(router_addr),
-                None => true,
-            } {
+            if !self.any_ip ||
+                    self.routes.lookup(&IpAddress::Ipv4(ipv4_repr.dst_addr), timestamp)
+                        .map_or(true, |router_addr| !self.has_ip_addr(router_addr)) {
                 return Ok(None);
             }
         }
@@ -1188,10 +1185,9 @@ impl<'b, 'c, 'e> InterfaceInner<'b, 'c, 'e> {
                 let ip_addr = ip_repr.src_addr.into();
                 match lladdr {
                     Some(lladdr) if lladdr.is_unicast() && target_addr.is_unicast() => {
-                        if flags.contains(NdiscNeighborFlags::OVERRIDE) {
+                        if flags.contains(NdiscNeighborFlags::OVERRIDE) ||
+                                !self.neighbor_cache.lookup(&ip_addr, timestamp).found() {
                             self.neighbor_cache.fill(ip_addr, lladdr, timestamp)
-                        } else if !self.neighbor_cache.lookup(&ip_addr, timestamp).found() {
-                                self.neighbor_cache.fill(ip_addr, lladdr, timestamp)
                         }
                     },
                     _ => (),
diff --git a/src/lib.rs b/src/lib.rs
index 7d18e89..7198b57 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -87,9 +87,6 @@
                feature = "socket-tcp")))]
 compile_error!("at least one socket needs to be enabled"); */
 
-// FIXME(dlrobertson): clippy fails with this lint
-#![allow(clippy::if_same_then_else)]
-#![allow(clippy::manual_non_exhaustive)]
 #![allow(clippy::match_like_matches_macro)]
 #![allow(clippy::redundant_field_names)]
 #![allow(clippy::identity_op)]
diff --git a/src/phy/mod.rs b/src/phy/mod.rs
index adf0597..e21963b 100644
--- a/src/phy/mod.rs
+++ b/src/phy/mod.rs
@@ -158,6 +158,7 @@ impl Checksum {
 
 /// A description of checksum behavior for every supported protocol.
 #[derive(Debug, Clone, Default)]
+#[non_exhaustive]
 pub struct ChecksumCapabilities {
     pub ipv4: Checksum,
     pub udp: Checksum,
@@ -166,7 +167,6 @@ pub struct ChecksumCapabilities {
     pub icmpv4: Checksum,
     #[cfg(feature = "proto-ipv6")]
     pub icmpv6: Checksum,
-    dummy: (),
 }
 
 impl ChecksumCapabilities {
@@ -181,7 +181,6 @@ impl ChecksumCapabilities {
             icmpv4: Checksum::None,
             #[cfg(feature = "proto-ipv6")]
             icmpv6: Checksum::None,
-            ..Self::default()
         }
     }
 }
@@ -191,6 +190,7 @@ impl ChecksumCapabilities {
 /// Higher-level protocols may achieve higher throughput or lower latency if they consider
 /// the bandwidth or packet size limitations.
 #[derive(Debug, Clone, Default)]
+#[non_exhaustive]
 pub struct DeviceCapabilities {
     /// Maximum transmission unit.
     ///
@@ -214,10 +214,6 @@ pub struct DeviceCapabilities {
     /// If the network device is capable of verifying or computing checksums for some protocols,
     /// it can request that the stack not do so in software to improve performance.
     pub checksum: ChecksumCapabilities,
-
-    /// Only present to prevent people from trying to initialize every field of DeviceLimits,
-    /// which would not let us add new fields in the future.
-    pub(crate) dummy: ()
 }
 
 /// An interface for sending and receiving raw network frames.
diff --git a/src/socket/tcp.rs b/src/socket/tcp.rs
index 346cd4a..2edccb8 100644
--- a/src/socket/tcp.rs
+++ b/src/socket/tcp.rs
@@ -1905,6 +1905,7 @@ impl<'a> TcpSocket<'a> {
         Ok(())
     }
 
+    #[allow(clippy::if_same_then_else)]
     pub(crate) fn poll_at(&self) -> PollAt {
         // The logic here mirrors the beginning of dispatch() closely.
         if !self.remote_endpoint.is_specified() {
diff --git a/src/wire/arp.rs b/src/wire/arp.rs
index e213b29..97fcf36 100644
--- a/src/wire/arp.rs
+++ b/src/wire/arp.rs
@@ -86,6 +86,7 @@ impl<T: AsRef<[u8]>> Packet<T> {
     ///
     /// [set_hardware_len]: #method.set_hardware_len
     /// [set_protocol_len]: #method.set_protocol_len
+    #[allow(clippy::if_same_then_else)]
     pub fn check_len(&self) -> Result<()> {
         let len = self.buffer.as_ref().len();
         if len < field::OPER.end {
diff --git a/src/wire/ipv4.rs b/src/wire/ipv4.rs
index aab7e61..6d51d41 100644
--- a/src/wire/ipv4.rs
+++ b/src/wire/ipv4.rs
@@ -271,6 +271,7 @@ impl<T: AsRef<[u8]>> Packet<T> {
     ///
     /// [set_header_len]: #method.set_header_len
     /// [set_total_len]: #method.set_total_len
+    #[allow(clippy::if_same_then_else)]
     pub fn check_len(&self) -> Result<()> {
         let len = self.buffer.as_ref().len();
         if len < field::DST_ADDR.end {