diff --git a/lib/responder.js b/lib/responder.js
index 2c6d965..821d985 100644
--- a/lib/responder.js
+++ b/lib/responder.js
@@ -17,8 +17,13 @@ module.exports = function (options, res, next) {
 		if (options.attribute) {
 			content = result[options.attribute];
 		}
-		// Set _Content-Type_ response header with `type` through `mime.lookup()`
-		res.type(options.ext);
+		if (options.ext) {
+			// Set _Content-Type_ response header with `type` through `mime.lookup()`
+			res.type(options.ext);
+		} else {
+			res.type('text/plain');
+		}
+
 		return res.send(content);
 	};
 };