diff --git a/manage_runner.sh b/manage_runner.sh
index c48f5b9..ecf9514 100755
--- a/manage_runner.sh
+++ b/manage_runner.sh
@@ -137,7 +137,7 @@ parse_runner_entry() {
 # Sets RUNNER_RESOLVED_IMAGE.
 # ---------------------------------------------------------------------------
 resolve_runner_image() {
-  local image="${RUNNER_DEFAULT_IMAGE:-${RUNNER_DEFAULT_IMAGE_ENV:-}}"
+  local image="${RUNNER_DEFAULT_IMAGE:-}"
   if [[ -z "$image" ]] && [[ "$RUNNER_TYPE" == "docker" ]]; then
     image="${RUNNER_DEFAULT_IMAGE:-catthehacker/ubuntu:act-latest}"
   fi