diff --git a/containers/core/standalone.Dockerfile b/containers/core/standalone.Dockerfile
index b07c657f..97e81563 100644
--- a/containers/core/standalone.Dockerfile
+++ b/containers/core/standalone.Dockerfile
@@ -54,9 +54,6 @@ FROM eval-base
 
 # ─── Gateway layer (uniform /opt/gateway/ contract) ──────────────────
 COPY --from=model /opt/gateway /opt/gateway
-# The gateway's start script needs envsubst (gettext-base) + curl at runtime;
-# both now ship in the benchmark base, so this layer stays pure COPY — no
-# per-combo apt (that emulated install under QEMU was the combo-build bottleneck).
 
 # ─── OTel collector layer ────────────────────────────────────────────
 COPY --from=otel /otelcol                 /usr/local/bin/otelcol
diff --git a/containers/gateways/bifrost/start b/containers/gateways/bifrost/start
index 18ece0ad..843b9211 100644
--- a/containers/gateways/bifrost/start
+++ b/containers/gateways/bifrost/start
@@ -49,9 +49,11 @@ if [ -f "$TEMPLATE" ]; then
   OTEL_COLLECTOR_URL="${OTEL_EXPORTER_OTLP_ENDPOINT%/}/v1/traces"
   export OTEL_COLLECTOR_URL
 
-  # Explicit var list so envsubst leaves bifrost's own $schema key alone.
-  envsubst '${PROVIDER} ${MODEL_NAME} ${OPENAI_API_BASE} ${OTEL_COLLECTOR_URL}' \
-    < "$TEMPLATE" > "$CONFIG"
+  sed -e "s|\${PROVIDER}|${PROVIDER-}|g" \
+      -e "s|\${MODEL_NAME}|${MODEL_NAME-}|g" \
+      -e "s|\${OPENAI_API_BASE}|${OPENAI_API_BASE-}|g" \
+      -e "s|\${OTEL_COLLECTOR_URL}|${OTEL_COLLECTOR_URL-}|g" \
+      < "$TEMPLATE" > "$CONFIG"
 fi
 
 exec /opt/gateway/main \
diff --git a/containers/gateways/litellm/start b/containers/gateways/litellm/start
index 08444eba..42361805 100644
--- a/containers/gateways/litellm/start
+++ b/containers/gateways/litellm/start
@@ -27,7 +27,7 @@ CONFIG=/opt/gateway/config.yaml
 
 if [ -f "$TEMPLATE" ]; then
   : "${EVAL_MODEL:?EVAL_MODEL must be set to <provider>/<model>}"
-  envsubst '${EVAL_MODEL}' < "$TEMPLATE" > "$CONFIG"
+  sed -e "s|\${EVAL_MODEL}|$EVAL_MODEL|g" < "$TEMPLATE" > "$CONFIG"
 fi
 
 # Caddy in background — listens on $PORT, forwards to litellm:4001.