diff --git a/backend/pashub_fetcher/tests/test_pashub_client.py b/backend/pashub_fetcher/tests/test_pashub_client.py
index ccf32fa6..8654a137 100644
--- a/backend/pashub_fetcher/tests/test_pashub_client.py
+++ b/backend/pashub_fetcher/tests/test_pashub_client.py
@@ -44,6 +44,18 @@ def test_get_core_file_type_returns_retrofit_design_doc_for_evidence_category()
     assert result == CoreFiles.RETROFIT_DESIGN_DOC
 
 
+def test_get_core_file_type_returns_improvement_option_evaluation_via_substring() -> None:
+    # Arrange
+    client = make_client()
+    file = make_file(file_name="6000802 - NG4 4HD - Improvement Option Evaluation.pdf")
+
+    # Act
+    result = client._get_core_file_type(file)
+
+    # Assert
+    assert result == CoreFiles.IMPROVEMENT_OPTION_EVALUATION
+
+
 def test_get_core_file_type_evidence_category_match_is_case_insensitive() -> None:
     # Arrange
     client = make_client()