diff --git a/generators/python/sdk/versions.yml b/generators/python/sdk/versions.yml
index 3fed5f09ad62..78f6d85fe261 100644
--- a/generators/python/sdk/versions.yml
+++ b/generators/python/sdk/versions.yml
@@ -1,5 +1,14 @@
 # yaml-language-server: $schema=../../../fern-versions-yml.schema.json
 # For unreleased changes, use unreleased.yml
+- version: 4.45.5
+  changelogEntry:
+    - summary: |
+        Fix file upload conditional check using wire_value instead of snake_case parameter name,
+        which caused mypy "name not defined" errors when the API field name differed from the
+        Python parameter name (e.g., `MyFile` vs `my_file`).
+      type: fix
+  createdAt: "2025-12-11"
+  irVersion: 61
 
 - version: 4.45.4
   changelogEntry:
diff --git a/generators/python/src/fern_python/generators/sdk/client_generator/request_body_parameters/file_upload_request_body_parameters.py b/generators/python/src/fern_python/generators/sdk/client_generator/request_body_parameters/file_upload_request_body_parameters.py
index 8ad06a2e82f3..a763a3fe6abd 100644
--- a/generators/python/src/fern_python/generators/sdk/client_generator/request_body_parameters/file_upload_request_body_parameters.py
+++ b/generators/python/src/fern_python/generators/sdk/client_generator/request_body_parameters/file_upload_request_body_parameters.py
@@ -195,7 +195,7 @@ def write_file_property(writer: AST.NodeWriter, file_property: ir_types.FileProp
                                 write_file_property(writer, property_as_union.value)
                                 writer.write("} ")
                                 writer.write_line(
-                                    f"if {property_as_union.value.get_as_union().key.wire_value} is not None "
+                                    f"if {self._get_file_property_name(property_as_union.value)} is not None "
                                 )
                                 writer.write_line("else {}")
                             writer.write_line("),")