diff --git a/.pre-commit-config.yaml b/.pre-commit-config.yaml
index 1216405..8d20e5b 100644
--- a/.pre-commit-config.yaml
+++ b/.pre-commit-config.yaml
@@ -25,7 +25,7 @@ repos:
                 ]
 
     - repo: https://github.com/myint/autoflake.git
-      rev: v1.4
+      rev: v2.3.0
       hooks:
           - id: autoflake
             args:
diff --git a/storage3/_async/file_api.py b/storage3/_async/file_api.py
index 3a947eb..47f7af4 100644
--- a/storage3/_async/file_api.py
+++ b/storage3/_async/file_api.py
@@ -368,12 +368,20 @@ async def _upload_or_update(
             file_options = {}
         cache_control = file_options.get("cache-control")
         _data = {}
+        if file_options.get("upsert"):
+            file_options.update({"x-upsert": file_options.get("upsert")})
+            del file_options["upsert"]
 
         headers = {
             **self._client.headers,
             **DEFAULT_FILE_OPTIONS,
             **file_options,
         }
+
+        # Only include x-upsert on a POST method
+        if method != "POST":
+            del headers["x-upsert"]
+
         filename = path.rsplit("/", maxsplit=1)[-1]
 
         if cache_control:
diff --git a/storage3/_sync/file_api.py b/storage3/_sync/file_api.py
index 18aa7e0..522e3a3 100644
--- a/storage3/_sync/file_api.py
+++ b/storage3/_sync/file_api.py
@@ -366,12 +366,20 @@ def _upload_or_update(
             file_options = {}
         cache_control = file_options.get("cache-control")
         _data = {}
+        if file_options.get("upsert"):
+            file_options.update({"x-upsert": file_options.get("upsert")})
+            del file_options["upsert"]
 
         headers = {
             **self._client.headers,
             **DEFAULT_FILE_OPTIONS,
             **file_options,
         }
+
+        # Only include x-upsert on a POST method
+        if method != "POST":
+            del headers["x-upsert"]
+
         filename = path.rsplit("/", maxsplit=1)[-1]
 
         if cache_control:
diff --git a/storage3/types.py b/storage3/types.py
index 9ae218f..1d9441c 100644
--- a/storage3/types.py
+++ b/storage3/types.py
@@ -77,6 +77,6 @@ class DownloadOptions(TypedDict, total=False):
 
 FileOptions = TypedDict(
     "FileOptions",
-    {"cache-control": str, "content-type": str, "x-upsert": str},
+    {"cache-control": str, "content-type": str, "x-upsert": str, "upsert": str},
     total=False,
 )