diff --git a/TelegramBotBase/BotBase.cs b/TelegramBotBase/BotBase.cs
index c7d865a..5a50823 100644
--- a/TelegramBotBase/BotBase.cs
+++ b/TelegramBotBase/BotBase.cs
@@ -265,7 +265,7 @@ public sealed class BotBase
     {
         foreach (var scope in BotCommandScopes)
         {
-            if (scope.Value.Any(a => "/" + a.Command == command))
+            if (scope.Value.Any(a => Constants.Telegram.BotCommandIndicator + a.Command == command))
             {
                 return true;
             }
diff --git a/TelegramBotBase/Commands/Extensions.cs b/TelegramBotBase/Commands/Extensions.cs
index 6a19ce1..e5b186d 100644
--- a/TelegramBotBase/Commands/Extensions.cs
+++ b/TelegramBotBase/Commands/Extensions.cs
@@ -1,4 +1,5 @@
-using System.Collections.Generic;
+using System;
+using System.Collections.Generic;
 using System.Linq;
 using Telegram.Bot.Types;
 
@@ -20,6 +21,16 @@ public static class Extensions
             scope = BotCommandScope.Default();
         }
 
+        if (string.IsNullOrEmpty(command))
+        {
+            throw new ArgumentNullException(nameof(command), $"{nameof(command)} parameter can not be null or empty");
+        }
+
+        if(command.StartsWith(Constants.Telegram.BotCommandIndicator))
+        {
+            throw new ArgumentException($"{nameof(command)} parameter does not have to start with a slash, please remove.", $"{nameof(command)}");
+        }
+
         var item = cmds.FirstOrDefault(a => a.Key.Type == scope.Type);
 
         if (item.Value != null)
diff --git a/TelegramBotBase/Constants/Telegram.cs b/TelegramBotBase/Constants/Telegram.cs
index f91642d..10b0eec 100644
--- a/TelegramBotBase/Constants/Telegram.cs
+++ b/TelegramBotBase/Constants/Telegram.cs
@@ -21,4 +21,10 @@ public static class Telegram
     /// The maximum length of callback data. Will raise an exception of it exceeds it.
     /// </summary>
     public const int MaxCallBackDataBytes = 64;
+
+
+    /// <summary>
+    /// The slash constant which indicates a bot command.
+    /// </summary>
+    public const string BotCommandIndicator = "/";
 }
\ No newline at end of file