diff --git a/.travis.yml b/.travis.yml
index 0833941..baeb288 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -2,6 +2,7 @@ language: go
 
 go:
   - 1.14.x
+  - 1.15.x
 
 before_install:
   - go get -t -v ./...
diff --git a/Makefile b/Makefile
new file mode 100644
index 0000000..b0505d0
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,4 @@
+generage:
+	rm -f *_sequence.go
+	go run cmd/generate/main.go
+
diff --git a/cmd/go.mod b/cmd/go.mod
index 2ac7b67..3e40638 100644
--- a/cmd/go.mod
+++ b/cmd/go.mod
@@ -1,3 +1,3 @@
 module github.com/gochore/timeseq/cmd
 
-go 1.14
+go 1.15
diff --git a/go.mod b/go.mod
index ae9a663..11eeeba 100644
--- a/go.mod
+++ b/go.mod
@@ -1,5 +1,5 @@
 module github.com/gochore/timeseq
 
-go 1.14
+go 1.15
 
 require github.com/gochore/pt v1.1.0