diff --git a/ipykernel/ipkernel.py b/ipykernel/ipkernel.py
index 5c450169..35945fbd 100644
--- a/ipykernel/ipkernel.py
+++ b/ipykernel/ipkernel.py
@@ -497,7 +497,7 @@ async def run(execution: Execution) -> None:
 
         return reply_content
 
-    def do_complete(self, code, cursor_pos):
+    async def do_complete(self, code, cursor_pos):
         """Handle code completion."""
         if _use_experimental_60_completion and self.use_experimental_completions:
             return self._experimental_do_complete(code, cursor_pos)
@@ -567,7 +567,7 @@ def _experimental_do_complete(self, code, cursor_pos):
             "status": "ok",
         }
 
-    def do_inspect(self, code, cursor_pos, detail_level=0, omit_sections=()):
+    async def do_inspect(self, code, cursor_pos, detail_level=0, omit_sections=()):
         """Handle code inspection."""
         name = token_at_cursor(code, cursor_pos)
 
@@ -595,7 +595,7 @@ def do_inspect(self, code, cursor_pos, detail_level=0, omit_sections=()):
 
         return reply_content
 
-    def do_history(
+    async def do_history(
         self,
         hist_access_type,
         output,
@@ -631,13 +631,13 @@ def do_history(
             "history": list(hist),
         }
 
-    def do_shutdown(self, restart):
+    async def do_shutdown(self, restart):
         """Handle kernel shutdown."""
         if self.shell:
             self.shell.exit_now = True
         return dict(status="ok", restart=restart)
 
-    def do_is_complete(self, code):
+    async def do_is_complete(self, code):
         """Handle an is_complete request."""
         transformer_manager = getattr(self.shell, "input_transformer_manager", None)
         if transformer_manager is None:
diff --git a/ipykernel/kernelbase.py b/ipykernel/kernelbase.py
index 20dcd7f8..5290fd1b 100644
--- a/ipykernel/kernelbase.py
+++ b/ipykernel/kernelbase.py
@@ -794,7 +794,7 @@ async def execute_request(self, socket, ident, parent):
             self._aborted_time = time.monotonic()
             self.log.info("Aborting queue")
 
-    def do_execute(
+    async def do_execute(
         self,
         code,
         silent,
@@ -829,7 +829,7 @@ async def complete_request(self, socket, ident, parent):
         matches = json_clean(matches)
         self.session.send(socket, "complete_reply", matches, parent, ident)
 
-    def do_complete(self, code, cursor_pos):
+    async def do_complete(self, code, cursor_pos):
         """Override in subclasses to find completions."""
         return {
             "matches": [],
@@ -865,7 +865,7 @@ async def inspect_request(self, socket, ident, parent):
         msg = self.session.send(socket, "inspect_reply", reply_content, parent, ident)
         self.log.debug("%s", msg)
 
-    def do_inspect(self, code, cursor_pos, detail_level=0, omit_sections=()):
+    async def do_inspect(self, code, cursor_pos, detail_level=0, omit_sections=()):
         """Override in subclasses to allow introspection."""
         return {"status": "ok", "data": {}, "metadata": {}, "found": False}
 
@@ -889,7 +889,7 @@ async def history_request(self, socket, ident, parent):
         msg = self.session.send(socket, "history_reply", reply_content, parent, ident)
         self.log.debug("%s", msg)
 
-    def do_history(
+    async def do_history(
         self,
         hist_access_type,
         output,
@@ -1020,7 +1020,7 @@ async def shutdown_request(self, socket, ident, parent):
 
         self.stop()
 
-    def do_shutdown(self, restart):
+    async def do_shutdown(self, restart):
         """Override in subclasses to do things when the frontend shuts down the
         kernel.
         """
@@ -1046,7 +1046,7 @@ async def is_complete_request(self, socket, ident, parent):
         reply_msg = self.session.send(socket, "is_complete_reply", reply_content, parent, ident)
         self.log.debug("%s", reply_msg)
 
-    def do_is_complete(self, code):
+    async def do_is_complete(self, code):
         """Override in subclasses to find completions."""
         return {"status": "unknown"}
 
diff --git a/pyproject.toml b/pyproject.toml
index ef49f0e4..9b2f3843 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -192,7 +192,8 @@ filterwarnings= [
   "ignore:unclosed database in <sqlite3.Connection:ResourceWarning",
 
   # ignore deprecated non async during tests:
-  "always:For consistency across implementations, it is recommended that:PendingDeprecationWarning",
+  "error:For consistency across implementations, it is recommended that:PendingDeprecationWarning",
+
 
 ]
 
diff --git a/tests/conftest.py b/tests/conftest.py
index 2c266555..22714c6e 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -168,7 +168,7 @@ def __init__(self, *args, **kwargs):
         self.shell = MagicMock()
         super().__init__(*args, **kwargs)
 
-    def do_execute(
+    async def do_execute(
         self, code, silent, store_history=True, user_expressions=None, allow_stdin=False
     ):
         if not silent: