diff --git a/.travis.yml b/.travis.yml
index f7a32d9b..5a54a241 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -3,6 +3,7 @@ language: go
 go:
   - 1.11.x
   - 1.12.x
+  - 1.13.x
 
 env:
   - GO111MODULE=on
diff --git a/go.mod b/go.mod
index 6e04a968..a675ec40 100644
--- a/go.mod
+++ b/go.mod
@@ -1,3 +1,5 @@
 module github.com/golang/mock
 
 require golang.org/x/tools v0.0.0-20190425150028-36563e24a262
+
+go 1.11