diff --git a/.travis.yml b/.travis.yml
index 1af8bc1b72..ece7425fe3 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -9,7 +9,7 @@ env:
 
 build: &rust_build
   language: rust
-  rust: stable
+  rust: 1.31.0
   script:
     - cargo gen-tests --verify
     - cargo gen-syntax --verify