diff --git a/.travis.yml b/.travis.yml
index cc8d6cc..1bc0c44 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -8,7 +8,7 @@ branches:
   # this avoids duplicate builds on the PR *branches*, too.)
   only:
     - master
-    - /^v\d+\.\d+(\.\d+)?(-\S*)?$/
+    - /^v\d+\.\d+(\.(\d|x)+)?(-\S*)?$/
 
 env:
   global: