diff --git a/packages/reporters/dev-server/src/templates/500.html b/packages/reporters/dev-server/src/templates/500.html
index 07d52ac66d5..ea7df0c3130 100644
--- a/packages/reporters/dev-server/src/templates/500.html
+++ b/packages/reporters/dev-server/src/templates/500.html
@@ -90,7 +90,7 @@ <h2 class="error-message"><%- error.message %></h2>
       // Reload the page when an HMR update occurs.
       var protocol =
         (location.protocol == 'https:' &&
-          !/localhost|127.0.0.1|0.0.0.0/.test(hostname))
+          !['localhost', '127.0.0.1', '0.0.0.0'].includes(hostname))
           ? 'wss'
           : 'ws';
       var hostname = <%- JSON.stringify(hmrOptions.host || null) %> || location.protocol.indexOf('http') === 0 ? location.hostname : 'localhost';
diff --git a/packages/runtimes/hmr/src/loaders/hmr-runtime.js b/packages/runtimes/hmr/src/loaders/hmr-runtime.js
index 9b060ea5b8a..2f691892489 100644
--- a/packages/runtimes/hmr/src/loaders/hmr-runtime.js
+++ b/packages/runtimes/hmr/src/loaders/hmr-runtime.js
@@ -93,7 +93,7 @@ if ((!parent || !parent.isParcelRequire) && typeof WebSocket !== 'undefined') {
   var protocol =
     HMR_SECURE ||
     (location.protocol == 'https:' &&
-      !/localhost|127.0.0.1|0.0.0.0/.test(hostname))
+      !['localhost', '127.0.0.1', '0.0.0.0'].includes(hostname))
       ? 'wss'
       : 'ws';