diff --git a/src/services/estimation_service_v2.py b/src/services/estimation_service_v2.py
index 2847f34..21d0c96 100644
--- a/src/services/estimation_service_v2.py
+++ b/src/services/estimation_service_v2.py
@@ -387,7 +387,7 @@ class EstimationService:
                     month_times = 120
                 elif medication.frequency in ["Weekly", "Once weekly"]:
                     month_times = 4
-                elif medication.frequency == ["Monthly", "One-time dose"]:
+                elif medication.frequency in ["Monthly", "One-time dose"]:
                     month_times = 1
                 elif medication.frequency == "Every other day":
                     month_times = 15