diff --git a/knack/commands.py b/knack/commands.py
index 2843f69..c268b69 100644
--- a/knack/commands.py
+++ b/knack/commands.py
@@ -124,7 +124,10 @@ def update_argument(self, param_name, argtype):
         # that coincides with the default
         if isinstance(arg_default, str):
             arg_default = DefaultStr(arg_default)
-        elif isinstance(arg_default, int):
+        elif isinstance(arg_default, int) and not isinstance(arg_default, bool):
+            # bool's is_default is ignored for now, because
+            # 1. bool is a subclass of int, so isinstance(True, int) cannot distinguish between int and bool
+            # 2. bool is not extendable according to https://stackoverflow.com/a/2172204/2199657
             arg_default = DefaultInt(arg_default)
         # update the default
         if arg_default: