diff --git a/.travis.yml b/.travis.yml
index fb3568b..1e89c1e 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,35 +1,37 @@
 language: rust
 matrix:
   include:
-    # litmus check that we work on stable/beta
-    # we don't, not until slice_rotate lands
+    ### Litmus check that we work on stable/beta
+    # (we don't, not until slice_rotate lands)
     # - rust: stable
     #   env: FEATURES='default' MODE='test'
     # - rust: beta
     #   env: FEATURES='default' MODE='test'
-    # actually test everything
+    ### Test default configurations
     - rust: nightly
       env: FEATURES='default' MODE='test'
     - rust: nightly
       env: FEATURES='default proto-ipv6' MODE='test'
+    ### Test select feature permutations, chosen to be as orthogonal as possible
     - rust: nightly
-      env: FEATURES='phy-raw_socket socket-udp' MODE='build'
+      env: FEATURES='std phy-raw_socket socket-udp' MODE='test'
     - rust: nightly
-      env: FEATURES='phy-tap_interface socket-udp' MODE='build'
+      env: FEATURES='std phy-tap_interface socket-udp' MODE='test'
     - rust: nightly
-      env: FEATURES='socket-raw' MODE='build'
+      env: FEATURES='std socket-raw' MODE='test'
     - rust: nightly
-      env: FEATURES='socket-udp' MODE='build'
+      env: FEATURES='std socket-udp' MODE='test'
     - rust: nightly
-      env: FEATURES='socket-tcp' MODE='build'
+      env: FEATURES='std socket-tcp' MODE='test'
     - rust: nightly
-      env: FEATURES='socket-icmp' MODE='build'
+      env: FEATURES='std socket-icmp' MODE='test'
+    ### Test select feature permutations, chosen to be as aggressive as possible
+    - rust: nightly
+      env: FEATURES='socket-raw socket-udp socket-tcp socket-icmp std' MODE='test'
+    - rust: nightly
+      env: FEATURES='socket-raw socket-udp socket-tcp socket-icmp alloc' MODE='test'
     - rust: nightly
       env: FEATURES='socket-raw socket-udp socket-tcp socket-icmp' MODE='build'
-    - rust: nightly
-      env: FEATURES='socket-raw socket-udp socket-tcp socket-icmp std' MODE='build'
-    - rust: nightly
-      env: FEATURES='socket-raw socket-udp socket-tcp socket-icmp alloc' MODE='build'
 script:
    - cargo "$MODE" --no-default-features --features "$FEATURES"
 notifications:
diff --git a/Cargo.toml b/Cargo.toml
index 8bb7309..9eb8734 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -48,18 +48,24 @@ default = [
 
 [[example]]
 name = "tcpdump"
-
-[[example]]
-name = "server"
-
-[[example]]
-name = "client"
+required-features = ["std", "phy-raw_socket"]
 
 [[example]]
 name = "httpclient"
+required-features = ["std", "phy-tap_interface", "proto-ipv4", "socket-tcp"]
 
 [[example]]
 name = "ping"
+required-features = ["std", "phy-tap_interface", "proto-ipv4", "socket-icmp"]
+
+[[example]]
+name = "server"
+required-features = ["std", "phy-tap_interface", "proto-ipv4", "socket-tcp", "socket-udp"]
+
+[[example]]
+name = "client"
+required-features = ["std", "phy-tap_interface", "proto-ipv4", "socket-tcp", "socket-udp"]
 
 [[example]]
 name = "loopback"
+required-features = ["alloc", "proto-ipv4"]
diff --git a/README.md b/README.md
index 65591ca..1b16f89 100644
--- a/README.md
+++ b/README.md
@@ -303,12 +303,12 @@ that do. Because of this, only one such example is provided.
 ### examples/loopback.rs
 
 _examples/loopback.rs_ sets up _smoltcp_ to talk with itself via a loopback interface.
-Although it does not require `std`, this example still requires the `collections` feature to run.
+Although it does not require `std`, this example still requires the `alloc` feature to run.
 
 Read its [source code](/examples/loopback.rs), then run it without `std`:
 
 ```sh
-cargo run --example loopback --no-default-features --features collections
+cargo run --example loopback --no-default-features --features alloc
 ```
 
 ... or with `std`:
diff --git a/src/iface/ethernet.rs b/src/iface/ethernet.rs
index e9b67d2..0290dc4 100644
--- a/src/iface/ethernet.rs
+++ b/src/iface/ethernet.rs
@@ -912,6 +912,7 @@ mod test {
     use wire::{IpAddress, IpCidr, IpProtocol, IpRepr};
     use wire::{Ipv4Address, Ipv4Repr};
     use wire::{Icmpv4Repr, Icmpv4DstUnreachable};
+    #[cfg(feature = "socket-udp")]
     use wire::{UdpPacket, UdpRepr};
 
     use super::Packet;
@@ -1039,6 +1040,7 @@ mod test {
     }
 
     #[test]
+    #[cfg(feature = "socket-udp")]
     fn test_icmp_error_port_unreachable() {
         static UDP_PAYLOAD: [u8; 12] = [
             0x48, 0x65, 0x6c, 0x6c,
diff --git a/src/lib.rs b/src/lib.rs
index 62773d8..8227604 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -84,6 +84,7 @@ extern crate libc;
 #[cfg(feature = "alloc")]
 extern crate alloc;
 #[cfg(any(test, feature = "log"))]
+#[allow(unused_imports)]
 #[macro_use(log, trace, debug)]
 extern crate log;