diff --git a/README.md b/README.md
index f416e0d..08bc889 100644
--- a/README.md
+++ b/README.md
@@ -212,17 +212,23 @@ Simply create a new `web.config` file in your projects `public` directory and pa
 </configuration>
 ```
 
-#### Troubleshoting
+#### Troubleshooting
 
-If you do not have a favicon.ico file in your project, you can get `404 Router::notFoundException()` constantly.
-To add `favicon.ico` as exception, you can add this line to the `<conditions>` group: 
-```<add input="{REQUEST_FILENAME}" negate="true" pattern="favicon.ico" ignoreCase="true" />```
+If you do not have a `favicon.ico` file in your project, you can get a `NotFoundHttpException` (404 - not found).
+To add `favicon.ico` to the IIS ignore-list, add the following line to the `<conditions>` group: 
+```
+<add input="{REQUEST_FILENAME}" negate="true" pattern="favicon.ico" ignoreCase="true" />
+```
 
 You can also make one exception for files with some extensions: 
-```<add input="{REQUEST_FILENAME}" pattern="\.ico|\.png|\.css|\.jpg" negate="true" ignoreCase="true" />```
+```
+<add input="{REQUEST_FILENAME}" pattern="\.ico|\.png|\.css|\.jpg" negate="true" ignoreCase="true" />
+```
 
-If you are using `$_SERVER['ORIG_PATH_INFO']`, you will get `\index.php\` as part of the returned value. By sample: 
-```/index.php/test/mypage.php```
+If you are using `$_SERVER['ORIG_PATH_INFO']`, you will get `\index.php\` as part of the returned value. For example: 
+```
+/index.php/test/mypage.php
+```
 
 ### Configuration
 
diff --git a/src/Pecee/SimpleRouter/SimpleRouter.php b/src/Pecee/SimpleRouter/SimpleRouter.php
index 2c545a2..c14e47e 100644
--- a/src/Pecee/SimpleRouter/SimpleRouter.php
+++ b/src/Pecee/SimpleRouter/SimpleRouter.php
@@ -427,7 +427,7 @@ class SimpleRouter
             $callback = $route->getCallback();
 
             /* Only add default namespace on relative callbacks */
-            if ($callback === null || $callback[0] !== '\\') {
+            if ($callback === null || (is_string($callback) === true && $callback[0] !== '\\')) {
 
                 $namespace = static::$defaultNamespace;