gistfile.diff

diff --git a/src/optimize/base_optimizer.js b/src/optimize/base_optimizer.js
index 79a116d4c6..9e859b9e37 100644
--- a/src/optimize/base_optimizer.js
+++ b/src/optimize/base_optimizer.js
@@ -240,6 +240,11 @@ export default class BaseOptimizer {
           test,
           include: /[\/\\]node_modules[\/\\]x-pack[\/\\]/,
           exclude: /[\/\\]node_modules[\/\\]x-pack[\/\\](.+?[\/\\])*node_modules[\/\\]/,
+        },
+        // TODO: remove when we drop support for IE11
+        {
+          test,
+          include: /[\/\\]node_modules[\/\\]normalize-url[\/\\]/
         }
       ];
     };