diff --git a/lib/index.js b/lib/index.js
index ea2f546..4faf27e 100644
--- a/lib/index.js
+++ b/lib/index.js
@@ -23,6 +23,7 @@ function plugin(opts) {
   opts.perPage  = opts.perPage || 0;
   opts.skipMetadata = opts.skipMetadata || false;
   opts.slug = opts.slug || {mode: 'rfc3986'};
+  opts.addMetadata = opts.addMetadata || {};
 
   return function(files, metalsmith, done) {
     /**
@@ -182,6 +183,9 @@ function plugin(opts) {
         pages.push(page);
       }
     }
+    
+    // add additional metadata
+    Object.assign(metadata, opts.addMetadata);
 
     // update metadata
     if (!opts.skipMetadata) {