diff --git a/.travis.yml b/.travis.yml
index ce3b134..e15070e 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,15 +1,15 @@
 language: rust
 rust:
-  - 1.36.0
-  - 1.37.0
-  # error on cfg(doctest)
-  # - 1.38.0
-  # - 1.39.0
   - 1.40.0
   - 1.41.0
   - 1.42.0
   - 1.43.0
   - 1.44.0
+  - 1.45.0
+  - 1.46.0
+  - 1.47.0
+  - 1.48.0
+  - 1.49.0
   - stable
   - beta
   - nightly