diff --git a/.travis.yml b/.travis.yml
index 053abfe1dc5ab93fcbc51ab25954567dbb3743a7..6acf0a80641baa5dc5c0fdb56be2012aa2db328d 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -53,7 +53,8 @@ matrix:
     - env: TARGET=arm-unknown-linux-musleabihf
     - env: TARGET=aarch64-unknown-linux-gnu
     - env: TARGET=aarch64-unknown-linux-musl
-      rust: beta
+      # FIXME(#856)
+      rust: 1.22.1
     - os: osx
       osx_image: xcode8.2
       env: TARGET=i386-apple-ios