diff --git a/.travis.yml b/.travis.yml
index 0ebe15b..c81c26c 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,12 +1,17 @@
 language: rust
 sudo: false
+rust:
+  - stable
+  - beta
+  - nightly
 
 after_success:
   - curl https://stainless-steel.github.io/travis/after_success.sh | bash
 
 env:
   global:
-    secure: aa3KwhwOTko0kDf7cbxa2ADbPihtvMnZsbIi/GFzNYVqLeLTWAuSph3uLzJACP9auitpOxIzvYvTGm4Btck1khwclOBR1dzZ6GKxvMjiW9ln9bCRV1rim+68ESdLHTRftJOkvzwX5tcLaBO5ib9RGNTe7wPBZdT4Q9NPuTJAyjvafhYvvtrZGwxmlNYWFzSooPHPYLb4CU/ffuxKFXfOCjlYU1W6FhQhrSzURTnVcIvW+zwVtqiJcVRbQkO+RZ+NY3c1MR4JMap3H9/MPO5Ff6+vjC1gLuAj9OocqgOWKvMXFL570mSIfSKn6KWPZf93xIGh7Y/BTiqi5jGZffZ1TWGv1xLOFGfN5FrWUzjb2l3hALHBv1te8TJnAHcEjSFTVOngvWR9lpblxpPZQWK5aC1noBA0JUFrk/9Xowk335SK4M0IViAERH7yXMJRah4bMSMEGvcs6KQmEq8u00fHz4hXXjbQpOXDoKRAdIwtwiZAE8N253xK36bew+TfQaDjh6xDcGMhuO09yyaryEl1fYpeoWmQ4qLIVURTl1i202OkeoLqPucCzz1GWX20UdWsVh9HVALxeFcGQtGbEEzKwzBr4OvJBmuet78rc1aB9Uv8u8me1m0vd/o2PmvPREu7ajVm6+Bk9/W96vtmK0CqkrGmzw5G90LOwUkXok+anzU=
+    - RUSTDOC_VERSION=nightly
+    - secure: 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
 
 notifications:
   email: false