diff --git a/lib/adapters/http.js b/lib/adapters/http.js
index afb44111d0..493725031f 100755
--- a/lib/adapters/http.js
+++ b/lib/adapters/http.js
@@ -203,7 +203,7 @@ module.exports = function httpAdapter(config) {
               return true;
             }
             if (proxyElement[0] === '.' &&
-                parsed.hostname.substr(parsed.hostname.length - proxyElement.length) === proxyElement) {
+                parsed.hostname.slice(parsed.hostname.length - proxyElement.length) === proxyElement) {
               return true;
             }
 
diff --git a/lib/helpers/parseHeaders.js b/lib/helpers/parseHeaders.js
index 8af2cc7f1b..9b4bfc6eec 100644
--- a/lib/helpers/parseHeaders.js
+++ b/lib/helpers/parseHeaders.js
@@ -34,8 +34,8 @@ module.exports = function parseHeaders(headers) {
 
   utils.forEach(headers.split('\n'), function parser(line) {
     i = line.indexOf(':');
-    key = utils.trim(line.substr(0, i)).toLowerCase();
-    val = utils.trim(line.substr(i + 1));
+    key = utils.trim(line.slice(0, i)).toLowerCase();
+    val = utils.trim(line.slice(i + 1));
 
     if (key) {
       if (parsed[key] && ignoreDuplicateOf.indexOf(key) >= 0) {