diff --git a/pgo/full-headless-cage.sh b/pgo/full-headless-cage.sh
index ad5d0264..eacb0c33 100755
--- a/pgo/full-headless-cage.sh
+++ b/pgo/full-headless-cage.sh
@@ -8,7 +8,7 @@ blddir=$(realpath "${2}")
 runtime_dir=$(mktemp -d)
 trap "rm -rf '${runtime_dir}'" EXIT INT HUP TERM
 
-XDG_RUNTIME_DIR="${runtime_dir}" WLR_BACKENDS=headless cage "${srcdir}"/pgo/full-inner.sh "${srcdir}" "${blddir}"
+XDG_RUNTIME_DIR="${runtime_dir}" WLR_RENDERER=pixman WLR_BACKENDS=headless cage "${srcdir}"/pgo/full-inner.sh "${srcdir}" "${blddir}"
 
 # Cage’s exit code doesn’t reflect our script’s exit code
 [ -f "${blddir}"/pgo-ok ] || exit 1
diff --git a/pgo/full-headless-sway.sh b/pgo/full-headless-sway.sh
index bbf038b9..48dbcb94 100755
--- a/pgo/full-headless-sway.sh
+++ b/pgo/full-headless-sway.sh
@@ -18,7 +18,7 @@ trap cleanup EXIT INT HUP TERM
 > "${sway_conf}" echo "exec '${srcdir}'/pgo/full-headless-sway-inner.sh '${srcdir}' '${blddir}'"
 
 # Run Sway. full-headless-sway-inner.sh ends with a ‘swaymsg exit’
-XDG_RUNTIME_DIR="${runtime_dir}" WLR_BACKENDS=headless sway -c "${sway_conf}"
+XDG_RUNTIME_DIR="${runtime_dir}" WLR_RENDERER=pixman WLR_BACKENDS=headless sway -c "${sway_conf}"
 
 # Sway’s exit code doesn’t reflect our script’s exit code
 [ -f "${blddir}"/pgo-ok ] || exit 1