diff --git a/.travis.yml b/.travis.yml
index e8076d10..7eb66bb1 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -16,7 +16,7 @@ matrix:
 
     # The earliest stable Rust version that works
     - env: TARGET=x86_64-unknown-linux-gnu
-      rust: 1.31.0
+      rust: 1.33.0
 
 
 before_install: set -e
diff --git a/appveyor.yml b/appveyor.yml
index 10cd4622..4e22ef12 100644
--- a/appveyor.yml
+++ b/appveyor.yml
@@ -10,7 +10,7 @@ environment:
 
   matrix:
     - target: x86_64-pc-windows-msvc
-      RUST_VERSION: 1.31.0
+      RUST_VERSION: 1.33.0
     - target: x86_64-pc-windows-msvc
       RUST_VERSION: stable