diff --git a/go.mod b/go.mod
index baac12e..d872453 100644
--- a/go.mod
+++ b/go.mod
@@ -1,3 +1,8 @@
 module github.com/go-language-server/uri
 
-require github.com/google/go-cmp v0.3.0
+go 1.12
+
+require (
+	github.com/google/go-cmp v0.3.0
+	golang.org/x/xerrors v0.0.0-20190516184347-8115aa61538e
+)
diff --git a/go.sum b/go.sum
new file mode 100644
index 0000000..01f2a80
--- /dev/null
+++ b/go.sum
@@ -0,0 +1,4 @@
+github.com/google/go-cmp v0.3.0 h1:crn/baboCvb5fXaQ0IJ1SGTsTVrWpDsCWC8EGETZijY=
+github.com/google/go-cmp v0.3.0/go.mod h1:8QqcDgzrUqlUb/G2PQTWiueGozuR1884gddMywk6iLU=
+golang.org/x/xerrors v0.0.0-20190516184347-8115aa61538e h1:GZc5hJQaj9QwsCgIB16JPWkpIiZB3PjXyUrl01otLII=
+golang.org/x/xerrors v0.0.0-20190516184347-8115aa61538e/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=