diff --git a/lib/express-load.js b/lib/express-load.js
index cc3f4f8..c4a511e 100644
--- a/lib/express-load.js
+++ b/lib/express-load.js
@@ -238,7 +238,17 @@ ExpressLoad.prototype.into = function(instance, done) {
           next();
         });
       } else if (typeof mod === 'function') {
-        mod = mod.call(script, instance);
+        // Instance it as function or class
+        try {
+          mod = mod.call(script, instance);
+        } catch(e) {
+          // If the error is a TypeError, try to call it as a class constructor
+          if (e.name === 'TypeError') {
+            mod = new mod(instance);
+          } else {
+            throw e;
+          }
+        }
       }
     }