diff --git a/airflow/utils/log/secrets_masker.py b/airflow/utils/log/secrets_masker.py
index 3177c58d14525..2fd0d0aaf97ad 100644
--- a/airflow/utils/log/secrets_masker.py
+++ b/airflow/utils/log/secrets_masker.py
@@ -16,7 +16,6 @@
 # under the License.
 """Mask sensitive information from logs"""
 import collections
-import io
 import logging
 import re
 from typing import TYPE_CHECKING, Iterable, Optional, Set, TypeVar, Union
@@ -178,7 +177,7 @@ def _redact_all(self, item: "RedactableItem") -> "RedactableItem":
         elif isinstance(item, (tuple, set)):
             # Turn set in to tuple!
             return tuple(self._redact_all(subval) for subval in item)
-        elif isinstance(item, Iterable):
+        elif isinstance(item, list):
             return list(self._redact_all(subval) for subval in item)
         else:
             return item
@@ -209,12 +208,11 @@ def redact(self, item: "RedactableItem", name: str = None) -> "RedactableItem":
             elif isinstance(item, (tuple, set)):
                 # Turn set in to tuple!
                 return tuple(self.redact(subval) for subval in item)
-            elif isinstance(item, io.IOBase):
-                return item
-            elif isinstance(item, Iterable):
+            elif isinstance(item, list):
                 return list(self.redact(subval) for subval in item)
             else:
                 return item
+        # I think this should never happen, but it does not hurt to leave it just in case
         except Exception as e:  # pylint: disable=broad-except
             log.warning(
                 "Unable to redact %r, please report this via <https://github.com/apache/airflow/issues>. "
diff --git a/tests/utils/log/test_secrets_masker.py b/tests/utils/log/test_secrets_masker.py
index 24e86c1b297f6..5d3b40404d9fd 100644
--- a/tests/utils/log/test_secrets_masker.py
+++ b/tests/utils/log/test_secrets_masker.py
@@ -72,22 +72,6 @@ def test_args(self, logger, caplog):
 
         assert caplog.text == "INFO Cannot connect to user:***\n"
 
-    def test_non_redactable(self, logger, caplog):
-        class NonReactable:
-            def __iter__(self):
-                raise RuntimeError("force fail")
-
-            def __repr__(self):
-                return "<NonRedactable>"
-
-        logger.info("Logging %s", NonReactable())
-
-        assert caplog.messages == [
-            "Unable to redact <NonRedactable>, please report this via "
-            + "<https://github.com/apache/airflow/issues>. Error was: RuntimeError: force fail",
-            "Logging <NonRedactable>",
-        ]
-
     def test_extra(self, logger, caplog):
         logger.handlers[0].formatter = ShortExcFormatter("%(levelname)s %(message)s %(conn)s")
         logger.info("Cannot connect", extra={'conn': "user:password"})