diff --git a/src/maggma/stores/mongolike.py b/src/maggma/stores/mongolike.py
index b6073d77a..b56941826 100644
--- a/src/maggma/stores/mongolike.py
+++ b/src/maggma/stores/mongolike.py
@@ -4,6 +4,7 @@
 various utilities.
 """
 
+import json
 import warnings
 from collections.abc import Iterator
 from itertools import chain, groupby
@@ -615,6 +616,7 @@ def __init__(
         serialization_option: Optional[int] = None,
         serialization_default: Optional[Callable[[Any], Any]] = None,
         encoding: Optional[str] = None,
+        sanitize_on_write: bool = False,
         **kwargs,
     ):
         """
@@ -640,6 +642,8 @@ def __init__(
                 encoding from the platform. This should work in the great majority of cases.
                 However, if you encounter a UnicodeDecodeError, consider setting the encoding
                 explicitly to 'utf8' or another encoding as appropriate.
+            sanitize_on_write: Whether to sanitize documents with jsanitize before writing to the
+                JSON file.
         """
         paths = paths if isinstance(paths, (list, tuple)) else [paths]
         self.paths = paths
@@ -669,6 +673,7 @@ def __init__(
         self.default_sort = None
         self.serialization_option = serialization_option
         self.serialization_default = serialization_default
+        self.sanitize_on_write = sanitize_on_write
 
         super().__init__(**kwargs)
 
@@ -767,12 +772,20 @@ def update_json_file(self):
             data = list(self.query())
             for d in data:
                 d.pop("_id")
-            bytesdata = orjson.dumps(
-                data,
-                option=self.serialization_option,
-                default=self.serialization_default,
-            )
-            f.write(bytesdata.decode("utf-8"))
+            if self.sanitize_on_write:
+                data = jsanitize(
+                    data,
+                    strict=False,
+                    recursive_msonable=True,
+                )
+                json.dump(data, f, indent=2)
+            else:
+                bytesdata = orjson.dumps(
+                    data,
+                    option=self.serialization_option,
+                    default=self.serialization_default,
+                )
+                f.write(bytesdata.decode("utf-8"))
 
     def __hash__(self):
         return hash((*self.paths, self.last_updated_field))
diff --git a/tests/stores/test_mongolike.py b/tests/stores/test_mongolike.py
index 997b7edde..259a59060 100644
--- a/tests/stores/test_mongolike.py
+++ b/tests/stores/test_mongolike.py
@@ -551,6 +551,31 @@ def test_jsonstore_last_updated(test_dir):
         assert jsonstore.last_updated > start_time
 
 
+def test_jsonstore_sanitize_on_write(test_dir):
+    class SubFloat(float):
+        pass
+
+    with ScratchDir("."):
+        jsonstore = JSONStore(
+            "sanitize.json",
+            read_only=False,
+            sanitize_on_write=True,
+        )
+        jsonstore.connect()
+
+        # This would fail on the normal orjson path, but should succeed when
+        # sanitize_on_write=True.
+        jsonstore.update({"wrong_field": SubFloat(1.1), "task_id": 3})
+        jsonstore.close()
+
+        # Confirm the file was written and can be reloaded.
+        jsonstore = JSONStore("sanitize.json", read_only=True)
+        jsonstore.connect()
+        doc = jsonstore.query_one(criteria={"task_id": 3})
+        assert doc is not None
+        assert doc["wrong_field"] == pytest.approx(1.1)
+
+
 def test_eq(mongostore, memorystore, jsonstore):
     assert mongostore == mongostore
     assert memorystore == memorystore