diff --git a/cdisc_rules_engine/services/reporting/base_report_data.py b/cdisc_rules_engine/services/reporting/base_report_data.py
index 5fc1612ec..4d1b351fd 100644
--- a/cdisc_rules_engine/services/reporting/base_report_data.py
+++ b/cdisc_rules_engine/services/reporting/base_report_data.py
@@ -49,8 +49,8 @@ def process_values(
             if value is None:
                 processed_values.append(null_placeholder)
                 continue
-            value = value.strip()
-            if value == "" or value.lower() == "nan":
+            stripped = value.strip()
+            if stripped == "" or stripped.lower() == "nan":
                 processed_values.append(null_placeholder)
             else:
                 processed_values.append(value)