diff --git a/.builds/linux.yml b/.builds/linux.yml
index d2257e90..6161bb71 100644
--- a/.builds/linux.yml
+++ b/.builds/linux.yml
@@ -46,6 +46,7 @@ tasks:
      cd gio/cmd
      go test ./...
      go test -race ./...
+     go test -modfile=go.local.mod ./...
  - test_example: |
      cd gio/example
      go test -race ./...
diff --git a/cmd/go.local.mod b/cmd/go.local.mod
new file mode 100644
index 00000000..774b55b4
--- /dev/null
+++ b/cmd/go.local.mod
@@ -0,0 +1,14 @@
+module gioui.org/cmd
+
+go 1.13
+
+require (
+	gioui.org v0.0.0-00010101000000-000000000000
+	github.com/chromedp/cdproto v0.0.0-20191114225735-6626966fbae4
+	github.com/chromedp/chromedp v0.5.2
+	golang.org/x/image v0.0.0-20190802002840-cff245a6509b
+	golang.org/x/sync v0.0.0-20190423024810-112230192c58
+	golang.org/x/tools v0.0.0-20190927191325-030b2cf1153e
+)
+
+replace gioui.org => ../
diff --git a/cmd/go.local.sum b/cmd/go.local.sum
new file mode 120000
index 00000000..c14a2974
--- /dev/null
+++ b/cmd/go.local.sum
@@ -0,0 +1 @@
+go.sum
\ No newline at end of file