diff --git a/.travis.yml b/.travis.yml
index c3d0a91..2acbb50 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -17,7 +17,7 @@ matrix:
 
     # Minimum Rust supported channel.
     - os: linux
-      rust: 1.31.0
+      rust: 1.40.0
       env: TARGET=x86_64-unknown-linux-gnu