diff --git a/.travis.yml b/.travis.yml
index e407929..c1f4f35 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,9 +1,9 @@
 language: perl
 perl:
-  - 5.18
-  - 5.20
-  - 5.22
-  - 5.24
+  - "5.18"
+  - "5.20"
+  - "5.22"
+  - "5.24"
 
 before_script:
   - cpanm --quiet --notest --skip-satisfied Devel::Cover::Report::Coveralls