diff --git a/MediaBrowser.Server.Implementations/Configuration/ServerConfigurationManager.cs b/MediaBrowser.Server.Implementations/Configuration/ServerConfigurationManager.cs
index 5ae3af5e2..db839a66e 100644
--- a/MediaBrowser.Server.Implementations/Configuration/ServerConfigurationManager.cs
+++ b/MediaBrowser.Server.Implementations/Configuration/ServerConfigurationManager.cs
@@ -96,10 +96,36 @@ namespace MediaBrowser.Server.Implementations.Configuration
 
             ValidateItemByNamePath(newConfig);
             ValidateTranscodingTempPath(newConfig);
+            ValidatePathSubstitutions(newConfig);
 
             base.ReplaceConfiguration(newConfiguration);
         }
 
+        private void ValidatePathSubstitutions(ServerConfiguration newConfig)
+        {
+            foreach (var map in newConfig.PathSubstitutions)
+            {
+                if (string.IsNullOrWhiteSpace(map.From) || string.IsNullOrWhiteSpace(map.To))
+                {
+                    throw new ArgumentException("Invalid path substitution");
+                }
+
+                if (!map.From.EndsWith(":\\") && !map.From.EndsWith(":/"))
+                {
+                    map.From = map.From.TrimEnd('/').TrimEnd('\\');
+                }
+                if (!map.To.EndsWith(":\\") && !map.To.EndsWith(":/"))
+                {
+                    map.To = map.To.TrimEnd('/').TrimEnd('\\');
+                }
+
+                if (string.IsNullOrWhiteSpace(map.From) || string.IsNullOrWhiteSpace(map.To))
+                {
+                    throw new ArgumentException("Invalid path substitution");
+                }
+            }
+        }
+
         /// <summary>
         /// Replaces the item by name path.
         /// </summary>