diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index c90ef595..a127d5b0 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -11,7 +11,7 @@ jobs:
     name: Build
     runs-on: ubuntu-16.04
     env:
-      GOFLAGS: -mod=readonly
+      GOFLAGS: -mod=vendor
 
     services:
       postgres: