diff --git a/lib/assets/tmpl-spec.jst b/lib/assets/tmpl-spec.jst
index 72cbbd0..181a7a5 100644
--- a/lib/assets/tmpl-spec.jst
+++ b/lib/assets/tmpl-spec.jst
@@ -80,7 +80,7 @@ function loadTemplate(file, exportName) {
         return { apply: function() { return e.stack; } };
     }
 }
-function reRequire(file, exportName) {
+function reRequire(file) {
     file = require.resolve(file);
     clearRequire(file);
     return require(file);
diff --git a/lib/node-configurator.js b/lib/node-configurator.js
index 065de2f..4c02a1b 100644
--- a/lib/node-configurator.js
+++ b/lib/node-configurator.js
@@ -37,6 +37,8 @@ exports.configure = function (config, options) {
     config.nodes(pattern, function (nodeConfig) {
         var langs = options.langs,
             engines = options.engines,
+            prependFiles = [].concat(options.prependFiles).filter(Boolean),
+            appendFiles = [].concat(options.appendFiles).filter(Boolean),
             coverageEngines = options.coverage.engines,
             engineTargets = [],
             specTargets = [],
@@ -70,17 +72,23 @@ exports.configure = function (config, options) {
             [files]
         ]);
 
-        // Add engines' techs
+        // Provide prepending and appending files if any.
+        prependFiles.concat(appendFiles)
+            .forEach(function (filepath) {
+                nodeConfig.addTech([provide, { target: filepath }]);
+            });
+
+        // Add engines' techs and set needsCoverage flag
         engines.forEach(function (engine) {
             engine.hasOwnProperty('needsCoverage') || (engine.needsCoverage = _.contains(coverageEngines, engine.name));
             nodeConfig.addTech([engine.tech, engine.options]);
         });
 
         // For each lang including no-lang (false) and mock-lang (true)
-        (Array.isArray(langs) ? langs : [langs && 'lang']).forEach(function (lang) {
-            var suffix = '.' + lang + '.js',
-                isMock = lang === 'lang',
-                isReal = lang && !isMock;
+        (Array.isArray(langs) ? langs : [langs && 'mock']).forEach(function (lang) {
+            var isMock = lang === 'mock',
+                isReal = !isMock && typeof lang === 'string',
+                suffix = '.' + (lang || 'merged') + '.js';
 
             // Keyset and lang file for real langs:
             isReal && nodeConfig.addTechs([
@@ -95,14 +103,17 @@ exports.configure = function (config, options) {
 
             engines.forEach(function (engine) {
                 var target = engine.target,
-                    destTarget = target;
+                    destTarget = target,
+                    sources = prependFiles.concat(target).concat(appendFiles);
 
                 // Skip block for `langs: false`
-                if (lang) {
+                // or if we don't need prepending/appending files.
+                if (lang || sources.length > 1) {
                     destTarget = target.replace('.js', suffix);
+                    lang && sources.unshift('?.lang' + suffix);
 
                     nodeConfig.addTech([mergeFile, {
-                        sources: ['?.lang' + suffix, target],
+                        sources: sources,
                         target: destTarget,
                         sourcemap: true
                     }]);
diff --git a/lib/plugin.js b/lib/plugin.js
index 1405714..08ee2e6 100644
--- a/lib/plugin.js
+++ b/lib/plugin.js
@@ -68,6 +68,8 @@ module.exports = function (helper, commonOpts) {
                 }),
                 langs: options.langs,
                 mockI18N: options.mockI18N,
+                prependFiles: options.prependFiles,
+                appendFiles: options.appendFiles,
                 engines: _.map(engines, function (engine, name) {
                     var techPath = engine.tech,
                         tech = require(techPath),
@@ -174,6 +176,8 @@ module.exports = function (helper, commonOpts) {
                     sourceLevels: options.sourceLevels,
                     langs: options.langs,
                     mockI18N: options.mockI18N,
+                    prependFiles: options.prependFiles,
+                    appendFiles: options.appendFiles,
                     engines: options.engines,
                     saveHtml: options.saveHtml,
                     coverage: options.coverage,