diff --git a/lib/proxy.js b/lib/proxy.js
index 9765704f16692b99284581cfb5f67ccb7ce848e3..531aa26dc202252ebfa845e37f547312c4323a62 100644
--- a/lib/proxy.js
+++ b/lib/proxy.js
@@ -4,7 +4,17 @@ module.exports = {
   bootstrap,
 };
 
+const envVars = ['HTTP_PROXY', 'HTTPS_PROXY', 'NO_PROXY'];
+
 function bootstrap() {
+  envVars.forEach(envVar => {
+    if (
+      typeof process.env[envVar] === 'undefined' &&
+      typeof process.env[envVar.toLowerCase()] !== 'undefined'
+    ) {
+      process.env[envVar] = process.env[envVar.toLowerCase()];
+    }
+  });
   return createGlobalProxyAgent({
     environmentVariableNamespace: '',
   });