diff --git a/dvc/command/config.py b/dvc/command/config.py
index ed2203c50..f536dd04c 100644
--- a/dvc/command/config.py
+++ b/dvc/command/config.py
@@ -50,21 +50,22 @@ class CmdConfig(CmdBaseNoRepo):
 
 
 parent_config_parser = argparse.ArgumentParser(add_help=False)
-parent_config_parser.add_argument(
+level_group = parent_config_parser.add_mutually_exclusive_group()
+level_group.add_argument(
     "--global",
     dest="level",
     action="store_const",
     const="global",
     help="Use global config.",
 )
-parent_config_parser.add_argument(
+level_group.add_argument(
     "--system",
     dest="level",
     action="store_const",
     const="system",
     help="Use system config.",
 )
-parent_config_parser.add_argument(
+level_group.add_argument(
     "--local",
     dest="level",
     action="store_const",