diff --git a/.travis.yml b/.travis.yml
index c8cda1b..6c498f4 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,6 +1,8 @@
 language: rust
 rust:
   - 1.8.0
+  - 1.15.0
+  - 1.20.0
   - stable
   - beta
   - nightly
diff --git a/ci/rustup.sh b/ci/rustup.sh
index 6b0eb78..436025f 100755
--- a/ci/rustup.sh
+++ b/ci/rustup.sh
@@ -5,7 +5,7 @@
 set -ex
 
 export TRAVIS_RUST_VERSION
-for TRAVIS_RUST_VERSION in 1.8.0 stable beta nightly; do
+for TRAVIS_RUST_VERSION in 1.8.0 1.15.0 1.20.0 stable beta nightly; do
     run="rustup run $TRAVIS_RUST_VERSION"
     $run $PWD/ci/test_full.sh
 done