diff --git a/internal/services/task_service.go b/internal/services/task_service.go
index f8f2d46..e0fe4d3 100644
--- a/internal/services/task_service.go
+++ b/internal/services/task_service.go
@@ -251,11 +251,10 @@ func (s *TaskService) UpdateTask(taskID, userID uint, req *requests.UpdateTaskRe
 	if req.DueDate != nil {
 		newDueDate := req.DueDate.ToTimePtr()
 		task.DueDate = newDueDate
-		// Also update NextDueDate if the task doesn't have completions yet
-		// (if it has completions, NextDueDate should be managed by completion logic)
-		if len(task.Completions) == 0 {
-			task.NextDueDate = newDueDate
-		}
+		// Always update NextDueDate when user explicitly edits due date.
+		// Completion logic will recalculate NextDueDate when task is completed,
+		// but manual edits should take precedence.
+		task.NextDueDate = newDueDate
 	}
 	if req.EstimatedCost != nil {
 		task.EstimatedCost = req.EstimatedCost