diff --git a/jupyter_core/application.py b/jupyter_core/application.py
index e55a657..1f7467f 100644
--- a/jupyter_core/application.py
+++ b/jupyter_core/application.py
@@ -37,7 +37,7 @@
 base_aliases: dict[str, t.Any] = {}
 if isinstance(Application.aliases, dict):
     # traitlets 5
-    base_aliases.update(Application.aliases)  # type:ignore[arg-type]
+    base_aliases.update(Application.aliases)
 _jupyter_aliases = {
     "log-level": "Application.log_level",
     "config": "JupyterApp.config_file",
@@ -47,7 +47,7 @@
 base_flags: dict[str, t.Any] = {}
 if isinstance(Application.flags, dict):
     # traitlets 5
-    base_flags.update(Application.flags)  # type:ignore[arg-type]
+    base_flags.update(Application.flags)
 _jupyter_flags: dict[str, t.Any] = {
     "debug": (
         {"Application": {"log_level": logging.DEBUG}},
@@ -72,8 +72,8 @@ class JupyterApp(Application):
     name = "jupyter"  # override in subclasses
     description = "A Jupyter Application"
 
-    aliases = base_aliases  # type:ignore[assignment]
-    flags = base_flags  # type:ignore[assignment]
+    aliases = base_aliases
+    flags = base_flags
 
     def _log_level_default(self) -> int:
         return logging.INFO
@@ -156,8 +156,6 @@ def ask() -> str:
                 return
 
         config_text = self.generate_config_file()
-        if isinstance(config_text, bytes):
-            config_text = config_text.decode("utf8")
         print("Writing default config to: %s" % config_file)
         ensure_dir_exists(os.path.abspath(os.path.dirname(config_file)), 0o700)
         with open(config_file, mode="w", encoding="utf-8") as f:
diff --git a/jupyter_core/command.py b/jupyter_core/command.py
index 81549fe..6bd5f1f 100644
--- a/jupyter_core/command.py
+++ b/jupyter_core/command.py
@@ -209,7 +209,7 @@ def _evaluate_argcomplete(parser: JupyterParser) -> list[str]:
         if cwords and len(cwords) > 1 and not cwords[1].startswith("-"):
             # If first completion word looks like a subcommand,
             # increment word from which to start handling arguments
-            increment_argcomplete_index()  # type:ignore[no-untyped-call]
+            increment_argcomplete_index()
             return cwords
         else:
             # Otherwise no subcommand, directly autocomplete and exit
diff --git a/pyproject.toml b/pyproject.toml
index ae05147..04f9276 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -88,7 +88,7 @@ nowarn = "test -W default {args}"
 
 [tool.hatch.envs.typing]
 features = ["test"]
-dependencies = ["mypy>=1.5.1", "traitlets>=5.10.1"]
+dependencies = ["mypy>=1.5.1", "traitlets>=5.11.2"]
 [tool.hatch.envs.typing.scripts]
 test = "mypy --install-types --non-interactive {args}"