diff --git a/tools/run-plan.sh b/tools/run-plan.sh
index f1039d2..2738bbe 100755
--- a/tools/run-plan.sh
+++ b/tools/run-plan.sh
@@ -5,14 +5,14 @@
 #
 # Usage:   tools/run-plan.sh docs/plans/M2a [FIRST]      FIRST is a task number such as 04
 # Options (environment):
-#   BOXMAKER_MODEL   model to use (default straylight/laguna-s-2.1; OpenCode's own default differs)
+#   OPENCODE_MODEL   model to use (default straylight/laguna-s-2.1; OpenCode's own default differs)
 #   OPENCODE_FLAGS   extra flags for `opencode run`, for example "--pure" or "--auto"
 #   DRY_RUN=1        print what would be run and stop
 set -eu
 
 plan="${1:?usage: tools/run-plan.sh docs/plans/<milestone> [FIRST]}"
 first="${2:-00}"
-model="${BOXMAKER_MODEL:-straylight/laguna-s-2.1}"
+model="${OPENCODE_MODEL:-straylight/laguna-s-2.1}"
 log=docs/implementer-log.md
 milestone=$(basename "$plan")
 runs=".state/runs/$milestone"