diff --git a/README.md b/README.md
index 767e5ca..a8af941 100644
--- a/README.md
+++ b/README.md
@@ -50,23 +50,26 @@ svr.listen_after_bind();
 ### Static File Server
 
 ```cpp
-svr.set_base_dir("./www"); // This is same as `svr.set_base_dir("./www", "/")`;
+auto ret = svr.set_base_dir("./www"); // This is same as `svr.set_base_dir("./www", "/")`;
+if (!ret) {
+  // The specified base directory doesn't exist...
+}
 
+// Mount /public to ./www directory
+ret = svr.set_base_dir("./www", "/public");
+
+// Mount /public to ./www1 and ./www2 directories
+ret = svr.set_base_dir("./www1", "/public"); // 1st order to search
+ret = svr.set_base_dir("./www2", "/public"); // 2nd order to search
+```
+
+```cpp
 // User defined file extension and MIME type mappings
 svr.set_file_extension_and_mimetype_mapping("cc", "text/x-c");
 svr.set_file_extension_and_mimetype_mapping("cpp", "text/x-c");
 svr.set_file_extension_and_mimetype_mapping("hh", "text/x-h");
 ```
 
-```cpp
-svr.set_base_dir("./www", "/public");
-```
-
-```cpp
-svr.set_base_dir("./www1", "/public"); // 1st order
-svr.set_base_dir("./www2", "/public"); // 2nd order
-```
-
 The followings are built-in mappings:
 
 | Extension  |     MIME Type          |
diff --git a/example/simplesvr.cc b/example/simplesvr.cc
index dcc97f6..c6f50bb 100644
--- a/example/simplesvr.cc
+++ b/example/simplesvr.cc
@@ -122,7 +122,10 @@ int main(int argc, const char **argv) {
   auto base_dir = "./";
   if (argc > 2) { base_dir = argv[2]; }
 
-  svr.set_base_dir(base_dir);
+  if (!svr.set_base_dir(base_dir)) {
+    cout << "The specified base directory doesn't exist...";
+    return 1;
+  }
 
   cout << "The server started at port " << port << "...";