diff --git a/hermes_cli/main.py b/hermes_cli/main.py
index 5150bfa1a7..3befd835cd 100644
--- a/hermes_cli/main.py
+++ b/hermes_cli/main.py
@@ -4033,7 +4033,7 @@ For more help on a command:
     chat_parser.add_argument(
         "-s", "--skills",
         action="append",
-        default=None,
+        default=argparse.SUPPRESS,
         help="Preload one or more skills for the session (repeat flag or comma-separate)"
     )
     chat_parser.add_argument(
@@ -4055,6 +4055,7 @@ For more help on a command:
     chat_parser.add_argument(
         "--resume", "-r",
         metavar="SESSION_ID",
+        default=argparse.SUPPRESS,
         help="Resume a previous session by ID (shown on exit)"
     )
     chat_parser.add_argument(
@@ -4062,14 +4063,14 @@ For more help on a command:
         dest="continue_last",
         nargs="?",
         const=True,
-        default=None,
+        default=argparse.SUPPRESS,
         metavar="SESSION_NAME",
         help="Resume a session by name, or the most recent if no name given"
     )
     chat_parser.add_argument(
         "--worktree", "-w",
         action="store_true",
-        default=False,
+        default=argparse.SUPPRESS,
         help="Run in an isolated git worktree (for parallel agents on the same repo)"
     )
     chat_parser.add_argument(
@@ -4088,13 +4089,13 @@ For more help on a command:
     chat_parser.add_argument(
         "--yolo",
         action="store_true",
-        default=False,
+        default=argparse.SUPPRESS,
         help="Bypass all dangerous command approval prompts (use at your own risk)"
     )
     chat_parser.add_argument(
         "--pass-session-id",
         action="store_true",
-        default=False,
+        default=argparse.SUPPRESS,
         help="Include the session ID in the agent's system prompt"
     )
     chat_parser.add_argument(
diff --git a/tests/hermes_cli/test_argparse_flag_propagation.py b/tests/hermes_cli/test_argparse_flag_propagation.py
new file mode 100644
index 0000000000..388f3aef50
--- /dev/null
+++ b/tests/hermes_cli/test_argparse_flag_propagation.py
@@ -0,0 +1,172 @@
+"""Tests for parent→subparser flag propagation.
+
+When flags like --yolo, -w, -s exist on both the parent parser and the 'chat'
+subparser, placing the flag BEFORE the subcommand (e.g. 'hermes --yolo chat')
+must not silently drop the flag value.
+
+Regression test for: argparse subparser default=False overwriting parent's
+parsed True when the same argument is defined on both parsers.
+
+Fix: chat subparser uses default=argparse.SUPPRESS for all duplicated flags,
+so the subparser only sets the attribute when the user explicitly provides it.
+"""
+
+import argparse
+import os
+import sys
+from unittest.mock import patch
+
+import pytest
+
+
+def _build_parser():
+    """Build the hermes argument parser from the real code.
+
+    We import the real main() and extract the parser it builds.
+    Since main() is a large function that does much more than parse args,
+    we replicate just the parser structure here to avoid side effects.
+    """
+    parser = argparse.ArgumentParser(prog="hermes")
+    parser.add_argument("--resume", "-r", metavar="SESSION", default=None)
+    parser.add_argument(
+        "--continue", "-c", dest="continue_last", nargs="?",
+        const=True, default=None, metavar="SESSION_NAME",
+    )
+    parser.add_argument("--worktree", "-w", action="store_true", default=False)
+    parser.add_argument("--skills", "-s", action="append", default=None)
+    parser.add_argument("--yolo", action="store_true", default=False)
+    parser.add_argument("--pass-session-id", action="store_true", default=False)
+
+    subparsers = parser.add_subparsers(dest="command")
+    chat = subparsers.add_parser("chat")
+    # These MUST use argparse.SUPPRESS to avoid overwriting parent values
+    chat.add_argument("--yolo", action="store_true",
+                      default=argparse.SUPPRESS)
+    chat.add_argument("--worktree", "-w", action="store_true",
+                      default=argparse.SUPPRESS)
+    chat.add_argument("--skills", "-s", action="append",
+                      default=argparse.SUPPRESS)
+    chat.add_argument("--pass-session-id", action="store_true",
+                      default=argparse.SUPPRESS)
+    chat.add_argument("--resume", "-r", metavar="SESSION_ID",
+                      default=argparse.SUPPRESS)
+    chat.add_argument(
+        "--continue", "-c", dest="continue_last", nargs="?",
+        const=True, default=argparse.SUPPRESS, metavar="SESSION_NAME",
+    )
+    return parser
+
+
+class TestFlagBeforeSubcommand:
+    """Flags placed before 'chat' must propagate through."""
+
+    def test_yolo_before_chat(self):
+        parser = _build_parser()
+        args = parser.parse_args(["--yolo", "chat"])
+        assert getattr(args, "yolo", False) is True
+
+    def test_worktree_before_chat(self):
+        parser = _build_parser()
+        args = parser.parse_args(["-w", "chat"])
+        assert getattr(args, "worktree", False) is True
+
+    def test_skills_before_chat(self):
+        parser = _build_parser()
+        args = parser.parse_args(["-s", "myskill", "chat"])
+        assert getattr(args, "skills", None) == ["myskill"]
+
+    def test_pass_session_id_before_chat(self):
+        parser = _build_parser()
+        args = parser.parse_args(["--pass-session-id", "chat"])
+        assert getattr(args, "pass_session_id", False) is True
+
+    def test_resume_before_chat(self):
+        parser = _build_parser()
+        args = parser.parse_args(["-r", "abc123", "chat"])
+        assert getattr(args, "resume", None) == "abc123"
+
+
+class TestFlagAfterSubcommand:
+    """Flags placed after 'chat' must still work."""
+
+    def test_yolo_after_chat(self):
+        parser = _build_parser()
+        args = parser.parse_args(["chat", "--yolo"])
+        assert getattr(args, "yolo", False) is True
+
+    def test_worktree_after_chat(self):
+        parser = _build_parser()
+        args = parser.parse_args(["chat", "-w"])
+        assert getattr(args, "worktree", False) is True
+
+    def test_skills_after_chat(self):
+        parser = _build_parser()
+        args = parser.parse_args(["chat", "-s", "myskill"])
+        assert getattr(args, "skills", None) == ["myskill"]
+
+    def test_resume_after_chat(self):
+        parser = _build_parser()
+        args = parser.parse_args(["chat", "-r", "abc123"])
+        assert getattr(args, "resume", None) == "abc123"
+
+
+class TestNoSubcommandDefaults:
+    """When no subcommand is given, flags must work and defaults must hold."""
+
+    def test_yolo_no_subcommand(self):
+        parser = _build_parser()
+        args = parser.parse_args(["--yolo"])
+        assert args.yolo is True
+        assert args.command is None
+
+    def test_defaults_no_flags(self):
+        parser = _build_parser()
+        args = parser.parse_args([])
+        assert getattr(args, "yolo", False) is False
+        assert getattr(args, "worktree", False) is False
+        assert getattr(args, "skills", None) is None
+        assert getattr(args, "resume", None) is None
+
+    def test_defaults_chat_no_flags(self):
+        parser = _build_parser()
+        args = parser.parse_args(["chat"])
+        # With SUPPRESS, these fall through to parent defaults
+        assert getattr(args, "yolo", False) is False
+        assert getattr(args, "worktree", False) is False
+        assert getattr(args, "skills", None) is None
+
+
+class TestYoloEnvVar:
+    """Verify --yolo sets HERMES_YOLO_MODE regardless of flag position.
+
+    This tests the actual cmd_chat logic pattern (getattr → os.environ).
+    """
+
+    @pytest.fixture(autouse=True)
+    def _clean_env(self):
+        os.environ.pop("HERMES_YOLO_MODE", None)
+        yield
+        os.environ.pop("HERMES_YOLO_MODE", None)
+
+    def _simulate_cmd_chat_yolo_check(self, args):
+        """Replicate the exact check from cmd_chat in main.py."""
+        if getattr(args, "yolo", False):
+            os.environ["HERMES_YOLO_MODE"] = "1"
+
+    def test_yolo_before_chat_sets_env(self):
+        parser = _build_parser()
+        args = parser.parse_args(["--yolo", "chat"])
+        self._simulate_cmd_chat_yolo_check(args)
+        assert os.environ.get("HERMES_YOLO_MODE") == "1"
+
+    def test_yolo_after_chat_sets_env(self):
+        parser = _build_parser()
+        args = parser.parse_args(["chat", "--yolo"])
+        self._simulate_cmd_chat_yolo_check(args)
+        assert os.environ.get("HERMES_YOLO_MODE") == "1"
+
+    def test_no_yolo_no_env(self):
+        parser = _build_parser()
+        args = parser.parse_args(["chat"])
+        self._simulate_cmd_chat_yolo_check(args)
+        assert os.environ.get("HERMES_YOLO_MODE") is None