diff --git a/gcsfs/core.py b/gcsfs/core.py
index dedf215b..ef43e49a 100644
--- a/gcsfs/core.py
+++ b/gcsfs/core.py
@@ -837,8 +837,8 @@ async def _mkdir(
         location=None,
         create_parents=True,
         enable_versioning=False,
-        uniform_access=False,
-        public_access_prevention=True,
+        enable_object_retention=False,
+        iam_configuration=None,
         **kwargs,
     ):
         """
@@ -846,7 +846,7 @@ async def _mkdir(
 
         If path is more than just a bucket, will create bucket if create_parents=True;
         otherwise is a noop. If create_parents is False and bucket does not exist,
-        will produce FileNotFFoundError.
+        will produce FileNotFoundError.
 
         Parameters
         ----------
@@ -854,7 +854,8 @@ async def _mkdir(
             bucket name. If contains '/' (i.e., looks like subdir), will
             have no effect because GCS doesn't have real directories.
         acl: string, one of bACLs
-            access for the bucket itself
+            access for the bucket itself. See:
+            https://cloud.google.com/storage/docs/access-control/lists#predefined-acl
         default_acl: str, one of ACLs
             default ACL for objects created in this bucket
         location: Optional[str]
@@ -867,12 +868,19 @@ async def _mkdir(
         enable_versioning: bool
             If True, creates the bucket in question with object versioning
             enabled.
-        uniform_access: bool
-            If True, creates the bucket in question with uniform access
-            enabled.
-        public_access_prevention: bool
-            If True, creates the bucket in question with public access
-            prevention enabled.
+        enable_object_retention: bool
+            If True, creates the bucket in question with object retention
+            permanently enabled.
+        iam_configuration: dict
+            If provided, sets the IAM policy for the bucket. This argument
+            allows setting properties such as `{publicAccessPrevention: "enforced"}`
+            and `{"uniformBucketLevelAccess": {"enabled": True}}`. If passed, `acl`
+            and `default_acl` are explicitly ignored.
+        **kwargs
+            Additional parameters passed to the API call request body. See:
+            https://cloud.google.com/storage/docs/json_api/v1/buckets/insert#request-body
+            for all possible options. Pass nested parameters as dictionaries, e.g.:
+            `{"autoclass": {"enabled": True}}`
         """
         bucket, object, generation = self.split_path(path)
         if bucket in ["", "/"]:
@@ -885,21 +893,18 @@ async def _mkdir(
                 return
             raise FileNotFoundError(bucket)
 
-        json_data = {"name": bucket, "iamConfiguration": {}}
+        json_data = {"name": bucket}
         location = location or self.default_location
         if location:
             json_data["location"] = location
         if enable_versioning:
             json_data["versioning"] = {"enabled": True}
-        if uniform_access:
-            # Cannot use ACLs with uniform access
+        if iam_configuration:
+            json_data["iamConfiguration"] = iam_configuration
             acl = None
             default_acl = None
-            json_data["iamConfiguration"]["uniformBucketLevelAccess"] = {
-                "enabled": True
-            }
-        if public_access_prevention:
-            json_data["iamConfiguration"]["publicAccessPrevention"] = "enforced"
+        if kwargs:
+            json_data.update(kwargs)
 
         await self._call(
             method="POST",
@@ -907,6 +912,7 @@ async def _mkdir(
             predefinedAcl=acl,
             project=self.project,
             predefinedDefaultObjectAcl=default_acl,
+            enableObjectRetention=str(enable_object_retention).lower(),
             json=json_data,
             json_out=True,
         )
diff --git a/gcsfs/tests/settings.py b/gcsfs/tests/settings.py
index a661417c..0e074f97 100644
--- a/gcsfs/tests/settings.py
+++ b/gcsfs/tests/settings.py
@@ -3,4 +3,3 @@
 TEST_BUCKET = os.getenv("GCSFS_TEST_BUCKET", "gcsfs_test")
 TEST_PROJECT = os.getenv("GCSFS_TEST_PROJECT", "project")
 TEST_REQUESTER_PAYS_BUCKET = "gcsfs_test_req_pay"
-TEST_CUSTOM_BUCKET = os.getenv("GCSFS_TEST_CUSTOM_BUCKET", "gcsfs_test_custom")
diff --git a/gcsfs/tests/test_core.py b/gcsfs/tests/test_core.py
index 6b51c018..1415d66f 100644
--- a/gcsfs/tests/test_core.py
+++ b/gcsfs/tests/test_core.py
@@ -24,7 +24,6 @@
 TEST_BUCKET = gcsfs.tests.settings.TEST_BUCKET
 TEST_PROJECT = gcsfs.tests.settings.TEST_PROJECT
 TEST_REQUESTER_PAYS_BUCKET = gcsfs.tests.settings.TEST_REQUESTER_PAYS_BUCKET
-TEST_CUSTOM_BUCKET = gcsfs.tests.settings.TEST_CUSTOM_BUCKET
 
 
 def test_simple(gcs):
@@ -1479,16 +1478,3 @@ def test_find_maxdepth(gcs):
 
     with pytest.raises(ValueError, match="maxdepth must be at least 1"):
         gcs.find(f"{TEST_BUCKET}/nested", maxdepth=0)
-
-
-def test_mkdir_options(gcs):
-    gcs = GCSFileSystem(endpoint_url=gcs._endpoint)
-    if not gcs.on_google:
-        pytest.skip("emulator doesn't support IAM policies.")
-
-    gcs.mkdir(TEST_CUSTOM_BUCKET, uniform_access=True, public_access_prevention=True)
-    info = gcs.info(TEST_CUSTOM_BUCKET)
-    gcs.rm(TEST_CUSTOM_BUCKET, recursive=True)
-
-    assert info["iamConfiguration"]["uniformBucketLevelAccess"]["enabled"]
-    assert info["iamConfiguration"]["publicAccessPrevention"] == "enforced"