diff --git a/README.md b/README.md
index 6100293..e5bd706 100644
--- a/README.md
+++ b/README.md
@@ -95,6 +95,42 @@ This creates a 32-bit executable at `target/i686-unknown-linux-gnu/release/telep
 
 I don't have a 32-bit machine to test this on, but happy to take fixes for it.
 
+### Cross-compiling amd64 -> aarch64
+
+This is a handy thing to do for linux phones, most of which use telepathy. Rust
+is quite heavy to compile - it's a pain even on a pinebook pro, which is the
+same architecture:
+
+```
+$ dpkg --print-architecture
+amd64
+# dpkg --add-architecture arm64
+$ dpkg --print-foreign-architectures
+arm64
+# apt update
+# apt install libdbus-1-dev:arm64 libssl-dev:arm64 gcc-aarch64-linux-gnu
+$ rustup target install aarch64-unknown-linux-gnu
+$ RUSTFLAGS="-C linker=aarch64-linux-gnu-gcc" PKG_CONFIG_ALLOW_CROSS=1 cargo build --target=aarch64-unknown-linux-gnu --release
+```
+
+We have to specify the linker because of [this bug](https://github.com/rust-lang/cargo/issues/4133).
+
+Note that this doesn't create a static binary, so you'll need to match versions
+for the shared libraries that are on the phone. In theory we can create static
+binaries with musl, but openssl makes it hard. If you get it working, tell me
+how!
+
+UBTouch uses an ancient version of OpenSSL: 1.0.2g. KDE Neon does much better
+with 1.1.1, so is easier to compile against. PostmarketOS is probably easiest of
+all.
+
+An alternative approach to using multiarch (as above) is to use `debootstrap`
+(or a similar tool) to get a sysroot containing libraries of all the right
+versions. E.g. You can then add `-C link-args=--sysroot=/path/to/sysroot` to
+`RUSTFLAGS` to use those libraries. Ufff. I've not got this working yet either.
+
+...I'm compiling it directly on the phone. Not ideal. Add swap.
+
 ### Installing
 
 There is a `share/` directory in this project that contains a bunch of files.
diff --git a/share/telepathy/managers/padfoot.manager b/share/telepathy/managers/padfoot.manager
index fd4fc64..3982731 100644
--- a/share/telepathy/managers/padfoot.manager
+++ b/share/telepathy/managers/padfoot.manager
@@ -5,7 +5,6 @@ BusName=org.freedesktop.Telepathy.ConnectionManager.padfoot
 ObjectPath=/org/freedesktop/Telepathy/ConnectionManager/padfoot
 
 [Protocol delta]
-Interfaces=org.freedesktop.Telepathy.Protocol.Interface.Presence;
 param-account=s required
 param-password=s required secret
 status-available=2 settable