diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 918db281f..49ba117ac 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -26,7 +26,7 @@ jobs:
         uses: actions/checkout@v4
       - name: Build
         env:
-          DISPLAY: 99
+          DISPLAY: :99
         run: |
           echo "Using display $DISPLAY"
           Xvfb $DISPLAY &