diff --git a/twitchio/authentication/oauth.py b/twitchio/authentication/oauth.py
index 343e59a3..247b4c72 100644
--- a/twitchio/authentication/oauth.py
+++ b/twitchio/authentication/oauth.py
@@ -29,6 +29,7 @@
 from typing import TYPE_CHECKING, ClassVar
 
 from ..http import HTTPClient, Route
+from ..utils import MISSING
 from .payloads import *
 
 
@@ -55,7 +56,7 @@ def __init__(
         client_secret: str,
         redirect_uri: str | None = None,
         scopes: Scopes | None = None,
-        session: aiohttp.ClientSession | None = None,
+        session: aiohttp.ClientSession = MISSING,
     ) -> None:
         super().__init__(session=session, client_id=client_id)
 
diff --git a/twitchio/authentication/tokens.py b/twitchio/authentication/tokens.py
index 4cde8b7b..b061b76e 100644
--- a/twitchio/authentication/tokens.py
+++ b/twitchio/authentication/tokens.py
@@ -37,6 +37,7 @@
 from ..exceptions import HTTPException, InvalidTokenException
 from ..http import HTTPAsyncIterator, PaginatedConverter
 from ..types_.tokens import TokenMappingData
+from ..utils import MISSING
 from .oauth import OAuth
 from .payloads import ClientCredentialsPayload, ValidateTokenPayload
 from .scopes import Scopes
@@ -61,7 +62,7 @@ def __init__(
         client_secret: str,
         redirect_uri: str | None = None,
         scopes: Scopes | None = None,
-        session: aiohttp.ClientSession | None = None,
+        session: aiohttp.ClientSession = MISSING,
         nested_key: str | None = None,
     ) -> None:
         super().__init__(
diff --git a/twitchio/http.py b/twitchio/http.py
index c4fe458b..13a6a569 100644
--- a/twitchio/http.py
+++ b/twitchio/http.py
@@ -377,11 +377,12 @@ async def __anext__(self) -> T:
 
 
 class HTTPClient:
-    __slots__ = ("_client_id", "_session", "_should_close", "user_agent")
+    __slots__ = ("_client_id", "_session", "_session_set", "_should_close", "user_agent")
 
     def __init__(self, session: aiohttp.ClientSession = MISSING, *, client_id: str) -> None:
         self._session: aiohttp.ClientSession = session
         self._should_close: bool = session is MISSING
+        self._session_set: bool = False
 
         self._client_id: str = client_id
 
@@ -395,6 +396,11 @@ def headers(self) -> dict[str, str]:
         return {"User-Agent": self.user_agent, "Client-ID": self._client_id}
 
     async def _init_session(self) -> None:
+        if self._session_set:
+            return
+
+        self._session_set = True
+
         if self._session is not MISSING:
             self._session.headers.update(self.headers)
             return
@@ -408,6 +414,7 @@ def clear(self) -> None:
                 "Clearing %s session. A new session will be created on the next request.", self.__class__.__qualname__
             )
             self._session = MISSING
+            self._session_set = False
 
     async def close(self) -> None:
         if not self._should_close: