diff --git a/Dockerfile b/Dockerfile
index 3e3331a5df..135c6abceb 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -57,7 +57,8 @@ LABEL org.opencontainers.image.title="omniroute" \
 ENV NODE_ENV=production
 ENV PORT=20128
 ENV HOSTNAME=0.0.0.0
-ENV NODE_OPTIONS="--max-old-space-size=256"
+ENV OMNIROUTE_MEMORY_MB=1024
+ENV NODE_OPTIONS="--max-old-space-size=${OMNIROUTE_MEMORY_MB}"
 
 # Data directory inside Docker — must match the volume mount in docker-compose.yml
 ENV DATA_DIR=/app/data
diff --git a/scripts/check-permissions.sh b/scripts/check-permissions.sh
index 13eedf45b0..45846806ca 100755
--- a/scripts/check-permissions.sh
+++ b/scripts/check-permissions.sh
@@ -1,6 +1,13 @@
 #!/bin/sh
 set -e
 
+# ── Memory limit override ──────────────────────────────────────────────
+# If OMNIROUTE_MEMORY_MB is set, build NODE_OPTIONS dynamically so the
+# user can tune heap size via environment without editing the Dockerfile.
+if [ -n "$OMNIROUTE_MEMORY_MB" ]; then
+  export NODE_OPTIONS="--max-old-space-size=${OMNIROUTE_MEMORY_MB} ${NODE_OPTIONS:-}"
+fi
+
 if [ -d "/app/data" ] && [ ! -w "/app/data" ]; then
     echo "WARNING: /app/data is not writable by the current user (UID $(id -u))."
     echo "Run this on the Docker host to fix:"