diff --git a/app/react/src/server/babel_config.js b/app/react/src/server/babel_config.js
index 7ed0bc5ca030..8eab74ed4283 100644
--- a/app/react/src/server/babel_config.js
+++ b/app/react/src/server/babel_config.js
@@ -66,11 +66,19 @@ export default function(configDir) {
   }
 
   const finalConfig = babelConfig || defaultConfig;
-  finalConfig.plugins = finalConfig.plugins || [];
-  finalConfig.plugins.push([
-    require.resolve('babel-plugin-react-docgen'),
-    { DOC_GEN_COLLECTION_NAME: 'STORYBOOK_REACT_CLASSES' },
-  ]);
+  // Ensure plugins are defined or fallback to an array to avoid empty values.
+  const babelConfigPlugins = finalConfig.plugins || [];
+  const extraPlugins = [
+    [
+      require.resolve('babel-plugin-react-docgen'),
+      {
+        DOC_GEN_COLLECTION_NAME: 'STORYBOOK_REACT_CLASSES',
+      },
+    ],
+  ];
+  // If `babelConfigPlugins` is not an `Array`, calling `concat` will inject it
+  // as a single value, if it is an `Array` it will be spreaded.
+  finalConfig.plugins = [].concat(babelConfigPlugins, extraPlugins);
 
   return finalConfig;
 }