diff --git a/assets/testing.stl b/assets/testing.stl
new file mode 100644
index 000000000..07c9bf8b7
Binary files /dev/null and b/assets/testing.stl differ
diff --git a/kittycad/api/file/file_convert_with_base64_helper.py b/kittycad/api/file/file_convert_with_base64_helper.py
index fa4c59615..e39f9226c 100644
--- a/kittycad/api/file/file_convert_with_base64_helper.py
+++ b/kittycad/api/file/file_convert_with_base64_helper.py
@@ -27,7 +27,7 @@ def sync(
         client=client,
     )
 
-    if fc.output != "":
+    if fc != None and fc.output != "":
         fc.output = base64.b64decode(fc.output)
 
     return fc
@@ -51,7 +51,7 @@ async def asyncio(
             client=client,
         )
 
-    if fc.output != "":
+    if fc != None and fc.output != "":
         fc.output = base64.b64decode(fc.output)
 
     return fc
diff --git a/kittycad/client_test.py b/kittycad/client_test.py
index 059138ff7..4a3593105 100644
--- a/kittycad/client_test.py
+++ b/kittycad/client_test.py
@@ -1,3 +1,4 @@
+import os
 import pytest
 import asyncio
 
@@ -74,3 +75,36 @@ async def test_ping_async():
     assert message != None
 
     print(f"Message: {message}")
+
+def test_file_convert_stl():
+    # Create our client.
+    client = AuthenticatedClientFromEnv()
+
+    dir_path = os.path.dirname(os.path.realpath(__file__))
+    file = open(os.path.join(dir_path, "../assets/testing.stl"), "rb")
+    content = file.read()
+    file.close()
+
+    # Get the fc.
+    fc: FileConversion = file_convert_with_base64_helper.sync(client=client, content=content, source_format=ValidFileTypes.STL, output_format=ValidFileTypes.OBJ)
+
+    assert fc != None
+
+    print(f"FileConversion: {fc}")
+
+@pytest.mark.asyncio
+async def test_file_convert_stl_async():
+    # Create our client.
+    client = AuthenticatedClientFromEnv()
+
+    dir_path = os.path.dirname(os.path.realpath(__file__))
+    file = open(os.path.join(dir_path, "../assets/testing.stl"), "rb")
+    content = file.read()
+    file.close()
+
+    # Get the fc.
+    fc: FileConversion = await file_convert_with_base64_helper.asyncio(client=client, content=content, source_format=ValidFileTypes.STL, output_format=ValidFileTypes.OBJ)
+
+    assert fc != None
+
+    print(f"FileConversion: {fc}")