diff --git a/requirements-testing.txt b/requirements-testing.txt
index 4a7176e..0bd8f2b 100644
--- a/requirements-testing.txt
+++ b/requirements-testing.txt
@@ -6,4 +6,5 @@ pytest-xdist ~= 3.3
 twine ~= 4.0
 mypy ~= 1.5
 black ~= 23.7
-ruff ~= 0.0.287
\ No newline at end of file
+ruff ~= 0.0.287
+types-PyYAML ~= 6.0.12
\ No newline at end of file
diff --git a/src/deadline/nuke_submitter/job_bundle_output_test_runner.py b/src/deadline/nuke_submitter/job_bundle_output_test_runner.py
index 9bf7ca4..b2088db 100644
--- a/src/deadline/nuke_submitter/job_bundle_output_test_runner.py
+++ b/src/deadline/nuke_submitter/job_bundle_output_test_runner.py
@@ -34,7 +34,6 @@
 from PySide2.QtWidgets import (  # pylint: disable=import-error; type: ignore
     QApplication,
     QFileDialog,
-    QMessageBox,
     QMainWindow,
 )
 
@@ -126,7 +125,7 @@ def _get_expected_nuke_version(expected_job_bundle_dir: str) -> str:
                     if parameter_value["name"] == "NukeVersion":
                         return parameter_value["value"]
 
-    return None
+    return ""
 
 
 # The following functions implement the test logic.