diff --git a/.github/workflows/build-xserver.yml b/.github/workflows/build-xserver.yml
index 690094d3c7..6b5eb71de7 100644
--- a/.github/workflows/build-xserver.yml
+++ b/.github/workflows/build-xserver.yml
@@ -15,7 +15,7 @@ on:
 jobs:
     xserver-build-ubuntu:
         env:
-            MESON_ARGS: -Dprefix=/usr -Dxephyr=true -Dwerror=false -Dxcsecurity=true -Dxorg=true -Dxvfb=true -Dxnest=true -Dxfbdev=true -Dtest_xephyr_gles=false
+            MESON_ARGS: -Dprefix=/usr -Dxephyr=true -Dwerror=true -Dxcsecurity=true -Dxorg=true -Dxvfb=true -Dxnest=true -Dxfbdev=true -Dtest_xephyr_gles=false
             LIBGL_ALWAYS_SOFTWARE: 1
             GALLIUM_DRIVER: llvmpipe
             PIGLIT_PLATFORM: x11_egl