diff --git a/index.js b/index.js
index 4927e22..2619a93 100644
--- a/index.js
+++ b/index.js
@@ -1,30 +1,44 @@
-module.exports = (nextConfig = {}) => {
+// ts-check
+
+/**
+ * @typedef {Object} Options
+ * @property {Array.<string|RegExp>} [include] - Additional directories to include
+ */
+
+/**
+ * @fileoverview Next.js plugin for loading GraphQL files
+ * @param {import('next').NextConfig} nextConfig
+ * @param {Options} [opts]
+ * @return {import('next').NextConfig}
+ */
+module.exports = (nextConfig = {}, opts = {}) => {
   return Object.assign({}, nextConfig, {
     webpack(config, options) {
       if (!options.defaultLoaders) {
         throw new Error(
-          'This plugin is not compatible with Next.js versions below 5.0.0 https://err.sh/next-plugins/upgrade'
-        )
+          "This plugin is not compatible with Next.js versions below 5.0.0 https://err.sh/next-plugins/upgrade"
+        );
       }
 
-      const { dir } = options
+      const { dir } = options;
+      const { include, exclude } = opts || {};
 
       config.module.rules.push({
         test: /\.(graphql|gql)$/,
-        include: [dir],
-        exclude: /node_modules/,
+        include: [dir].concat(include || []),
+        exclude: [/node_modules/].concat(exclude || []),
         use: [
           {
-            loader: 'graphql-tag/loader'
-          }
-        ]
-      })
+            loader: "graphql-tag/loader",
+          },
+        ],
+      });
 
-      if (typeof nextConfig.webpack === 'function') {
-        return nextConfig.webpack(config, options)
+      if (typeof nextConfig.webpack === "function") {
+        return nextConfig.webpack(config, options);
       }
 
-      return config
-    }
-  })
-}
+      return config;
+    },
+  });
+};