diff --git a/CHANGELOG.md b/CHANGELOG.md
index 4d18863cf..ba87df9e0 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,10 +1,11 @@
-## 0.17.11-dev1
+## 0.17.11-dev2
 
 ### Enhancements
 
 ### Features
 
 ### Fixes
+- Fix type error when `result_file_type` is expected to be a `FileType` but is `None`
 - Fix chunking for elements with None text that has AttributeError 'NoneType' object has no attribute 'strip'.
 - Invalid elements IDs are not visible in VLM output. Parent-child hierarchy is now retrieved based on unstructured element ID, instead of id injected into HTML code of element.
 
diff --git a/unstructured/__version__.py b/unstructured/__version__.py
index 1909f0042..b5c0cb697 100644
--- a/unstructured/__version__.py
+++ b/unstructured/__version__.py
@@ -1 +1 @@
-__version__ = "0.17.11-dev1"  # pragma: no cover
+__version__ = "0.17.11-dev2"  # pragma: no cover
diff --git a/unstructured/file_utils/filetype.py b/unstructured/file_utils/filetype.py
index 81557562f..1206b1e8b 100644
--- a/unstructured/file_utils/filetype.py
+++ b/unstructured/file_utils/filetype.py
@@ -222,18 +222,13 @@ class _FileTypeDetector:
         return FileType.from_mime_type(self._ctx.content_type)
 
     @property
-    def _disambiguate_json_file_type(self) -> FileType | None:
-        """Disambiguate JSON/NDJSON file-type based on file contents.
-
-        This method is used when the content-type is `application/json` and the file is not empty.
-        """
-        if self._ctx.content_type is not None and self._ctx.content_type != "application/json":
-            return None
+    def _disambiguate_json_file_type(self) -> FileType:
+        """Disambiguate JSON/NDJSON file-type based on file contents."""
         if is_json_processable(file_text=self._ctx.text_head):
             return FileType.JSON
         if is_ndjson_processable(file_text=self._ctx.text_head):
             return FileType.NDJSON
-        return None
+        raise ValueError("Unable to process JSON file")
 
     @property
     def _file_type_from_guessed_mime_type(self) -> FileType | None:
diff --git a/unstructured/partition/auto.py b/unstructured/partition/auto.py
index fa4c05034..d8555e824 100644
--- a/unstructured/partition/auto.py
+++ b/unstructured/partition/auto.py
@@ -226,7 +226,7 @@ def partition(
         )
         return augment_metadata(elements)
 
-    if file_type.partitioner_shortname == "image":
+    if file_type.partitioner_shortname and file_type.partitioner_shortname == "image":
         partition_image = partitioner_loader.get(file_type)
         elements = partition_image(
             filename=filename,