diff --git a/util/flags.py b/util/flags.py
index a4cb4979..468d8e50 100644
--- a/util/flags.py
+++ b/util/flags.py
@@ -2,10 +2,10 @@ from __future__ import absolute_import, division, print_function
 
 import tensorflow as tf
 
+import os
 
 FLAGS = tf.app.flags.FLAGS
 
-
 def create_flags():
     # Importer
     # ========
@@ -113,3 +113,26 @@ def create_flags():
     # Inference mode
 
     f.DEFINE_string('one_shot_infer', '', 'one-shot inference mode: specify a wav file and the script will load the checkpoint and perform inference on it.')
+
+    # Register validators for paths which require a file to be specified
+
+    f.register_validator('lm_binary_path',
+                         os.path.isfile,
+                         message='The file pointed to by --lm_binary_path must exist and be readable.')
+
+    f.register_validator('lm_trie_path',
+                         os.path.isfile,
+                         message='The file pointed to by --lm_trie_path must exist and be readable.')
+
+    f.register_validator('alphabet_config_path',
+                         os.path.isfile,
+                         message='The file pointed to by --alphabet_config_path must exist and be readable.')
+
+    f.register_validator('one_shot_infer',
+                         lambda value: not value or os.path.isfile(value),
+                         message='The file pointed to by --one_shot_infer must exist and be readable.')
+
+    f.register_validator('export_dir',
+                         lambda value: not value or os.path.isdir(value),
+                         message='The path pointed to by --export_dir must exist and be a directory.')
+