diff --git a/.travis.yml b/.travis.yml
index dae224e1a481144c90e8f81b63e116cdc60ece19..15083598be4e0726fba9aa4840687cef44533d82 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -5,6 +5,7 @@ cache: cargo
 before_script:
   - rustup component add rustfmt-preview
   - rustup target add x86_64-unknown-redox
+  - rustup target add aarch64-unknown-linux-gnu
 script:
   - bash ./ci.sh
 notifications:
diff --git a/Cargo.lock b/Cargo.lock
index 91daf313a39d98e65f51aca1affeaee0fb131df9..f2bdefd4a5261e3fd2c2c34996d0a79ddba7ed6b 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -31,6 +31,11 @@ dependencies = [
  "toml 0.4.5 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "cc"
+version = "1.0.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
 [[package]]
 name = "cfg-if"
 version = "0.1.2"
@@ -105,11 +110,6 @@ name = "fuchsia-zircon-sys"
 version = "0.3.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
-[[package]]
-name = "gcc"
-version = "0.3.54"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-
 [[package]]
 name = "grp"
 version = "0.1.0"
@@ -586,7 +586,7 @@ dependencies = [
 name = "va_list-helper"
 version = "0.0.2"
 dependencies = [
- "gcc 0.3.54 (registry+https://github.com/rust-lang/crates.io-index)",
+ "cc 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
@@ -635,13 +635,13 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 "checksum ansi_term 0.10.2 (registry+https://github.com/rust-lang/crates.io-index)" = "6b3568b48b7cefa6b8ce125f9bb4989e52fbcc29ebea88df04cc7c5f12f70455"
 "checksum atty 0.2.6 (registry+https://github.com/rust-lang/crates.io-index)" = "8352656fd42c30a0c3c89d26dea01e3b77c0ab2af18230835c15e2e13cd51859"
 "checksum bitflags 1.0.1 (registry+https://github.com/rust-lang/crates.io-index)" = "b3c30d3802dfb7281680d6285f2ccdaa8c2d8fee41f93805dba5c4cf50dc23cf"
+"checksum cc 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)" = "9be26b24e988625409b19736d130f0c7d224f01d06454b5f81d8d23d6c1a618f"
 "checksum cfg-if 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)" = "d4c819a1287eb618df47cc647173c5c4c66ba19d888a6e50d605672aed3140de"
 "checksum clap 2.30.0 (registry+https://github.com/rust-lang/crates.io-index)" = "1c07b9257a00f3fc93b7f3c417fc15607ec7a56823bc2c37ec744e266387de5b"
 "checksum compiler_builtins 0.1.0 (git+https://github.com/rust-lang-nursery/compiler-builtins.git)" = "<none>"
 "checksum dtoa 0.4.2 (registry+https://github.com/rust-lang/crates.io-index)" = "09c3753c3db574d215cba4ea76018483895d7bff25a31b49ba45db21c48e50ab"
 "checksum fuchsia-zircon 0.3.3 (registry+https://github.com/rust-lang/crates.io-index)" = "2e9763c69ebaae630ba35f74888db465e49e259ba1bc0eda7d06f4a067615d82"
 "checksum fuchsia-zircon-sys 0.3.3 (registry+https://github.com/rust-lang/crates.io-index)" = "3dcaa9ae7725d12cdb85b3ad99a434db70b468c09ded17e012d86b5c1010f7a7"
-"checksum gcc 0.3.54 (registry+https://github.com/rust-lang/crates.io-index)" = "5e33ec290da0d127825013597dbdfc28bee4964690c7ce1166cbc2a7bd08b1bb"
 "checksum itoa 0.3.4 (registry+https://github.com/rust-lang/crates.io-index)" = "8324a32baf01e2ae060e9de58ed0bc2320c9a2833491ee36cd3b4c414de4db8c"
 "checksum kernel32-sys 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)" = "7507624b29483431c0ba2d82aece8ca6cdba9382bff4ddd0f7490560c056098d"
 "checksum libc 0.2.37 (registry+https://github.com/rust-lang/crates.io-index)" = "56aebce561378d99a0bb578f8cb15b6114d2a1814a6c7949bbe646d968bb4fa9"
diff --git a/README.md b/README.md
index da2cd157a594d86263ebda30361ed29b8380c2fe..706c2548bbfe190afc9cdd1dced96531ecdaed8b 100644
--- a/README.md
+++ b/README.md
@@ -1,2 +1,12 @@
 # relibc ![build](https://travis-ci.org/redox-os/relibc.svg?branch=master)
 relibc is a portable POSIX C standard library written in Rust. It is under heavy development, and currently supports Redox and Linux.
+
+## Supported OSes
+
+ - RedoxOS
+ - Linux
+
+## Supported architectures
+
+ - x86\_64
+ - Aarch64
diff --git a/ci.sh b/ci.sh
index 6fe90aaf9e6d9f94d658d9700b2e1588ed7c94c7..fd7dd91a480ac2b1f8ee9d3230b3210b3367440d 100755
--- a/ci.sh
+++ b/ci.sh
@@ -4,3 +4,9 @@ set -ex
 ./fmt.sh -- --write-mode=diff
 ./test.sh
 cargo build --target=x86_64-unknown-redox
+if [ $(arch) == "x86_64" ]
+then
+    cargo build --target=aarch64-unknown-linux-gnu
+else
+    cargo build --target=x86_64-unknown-linux-gnu
+fi
diff --git a/tests/Makefile b/tests/Makefile
index 18f8e1911f9cbaf4eb49bd7d9adff3229884beda..24f1ba3a0443600b3e3d3433ca2f644ca1e9e223 100644
--- a/tests/Makefile
+++ b/tests/Makefile
@@ -17,7 +17,7 @@ BINS=\
 	link \
 	math \
 	pipe \
-	printf \ 
+	printf \
 	rmdir \
 	setid \
 	unlink \
diff --git a/va_list b/va_list
index 1945668b2fc6e96c498003dce700ebaf95108fac..ba5a07a744915b501acadb17e05db0f5d6552f72 160000
--- a/va_list
+++ b/va_list
@@ -1 +1 @@
-Subproject commit 1945668b2fc6e96c498003dce700ebaf95108fac
+Subproject commit ba5a07a744915b501acadb17e05db0f5d6552f72