diff --git a/.travis.yml b/.travis.yml
index 4faa6286..8cc512a7 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -4,13 +4,13 @@ dist: trusty
 os:
 - linux
 go:
-- 1.8.7
-- 1.9.3
-- "1.10.1"
-- tip
+- 1.8.x
+- 1.9.x
+- 1.10.x
+- master
 script:
 - go test ./...
 - GOARCH=386 go test ./...
 matrix:
   allow_failures:
-  - go: tip
+  - go: master
diff --git a/go.mod b/go.mod
new file mode 100644
index 00000000..be655164
--- /dev/null
+++ b/go.mod
@@ -0,0 +1,6 @@
+module github.com/go-python/gpython
+
+require (
+	github.com/mattn/go-runewidth v0.0.3 // indirect
+	github.com/peterh/liner v0.0.0-20180619022028-8c1271fcf47f
+)