diff --git a/src/healthcheck.js b/src/healthcheck.js
index ef3c3d7..b3a0ab0 100644
--- a/src/healthcheck.js
+++ b/src/healthcheck.js
@@ -1,9 +1,9 @@
 import * as http from 'http';
-var options = {
+const options = {
   timeout: 2000,
 };
-var url = 'http://localhost:8080/health';
-var request = http.request(url, options, (res) => {
+const url = 'http://localhost:8080/health';
+const request = http.request(url, options, (res) => {
   console.log(`STATUS: ${res.statusCode}`);
   if (res.statusCode == 200) {
     process.exit(0);
diff --git a/src/serve_rendered.js b/src/serve_rendered.js
index f8b33f7..1108992 100644
--- a/src/serve_rendered.js
+++ b/src/serve_rendered.js
@@ -765,7 +765,7 @@ export const serve_rendered = {
             image.resize(width * scale, height * scale);
           }
 
-          var composite_array = [];
+          const composite_array = [];
           if (opt_overlay) {
             composite_array.push({ input: opt_overlay });
           }