diff --git a/franz/silver_messages/directorial/execute_command.cs b/franz/silver_messages/directorial/execute_command.cs
index 732f8ce..88d28a0 100644
--- a/franz/silver_messages/directorial/execute_command.cs
+++ b/franz/silver_messages/directorial/execute_command.cs
@@ -6,7 +6,7 @@ namespace silver_messages.directorial
 {
     /*
      * if this is the name of one of your capabilities, pass args to it and execute it.
-     * if timeout is > 0, wait that long (in seconds) before terminating the command.
+     * if timeout is > 0 (and also not null), wait that long before terminating the command.
      * if the command completed, send a command_completed. if you had to kill it because
      * timeout, send command_expired. If it has no timeout, send command_output and
      * command_error as you get them, and if it ends some other way, send command_completed
@@ -16,6 +16,6 @@ namespace silver_messages.directorial
     {
         public string command { get; set; }
         public List<string> args { get; set; } = new List<string>();
-        public int timeout { get; set; }
+        public TimeSpan? timeout { get; set; }
     }
 }