diff --git a/internal/handlers/source_management.go b/internal/handlers/source_management.go
index 0c17039..61bfc2c 100644
--- a/internal/handlers/source_management.go
+++ b/internal/handlers/source_management.go
@@ -295,10 +295,30 @@ func (h *Handlers) HandleSourceDelete() http.HandlerFunc {
 			return
 		}
 
-		// Soft-delete child records
+		// Soft-delete child records in dependency order (deepest first).
+
+		// Collect event IDs for this webhook
+		var eventIDs []string
+		tx.Model(&database.Event{}).Where("webhook_id = ?", webhook.ID).Pluck("id", &eventIDs)
+
+		if len(eventIDs) > 0 {
+			// Collect delivery IDs for these events
+			var deliveryIDs []string
+			tx.Model(&database.Delivery{}).Where("event_id IN ?", eventIDs).Pluck("id", &deliveryIDs)
+
+			if len(deliveryIDs) > 0 {
+				// Soft-delete delivery results
+				tx.Where("delivery_id IN ?", deliveryIDs).Delete(&database.DeliveryResult{})
+			}
+
+			// Soft-delete deliveries
+			tx.Where("event_id IN ?", eventIDs).Delete(&database.Delivery{})
+		}
+
+		// Soft-delete events, entrypoints, targets, and the webhook itself
+		tx.Where("webhook_id = ?", webhook.ID).Delete(&database.Event{})
 		tx.Where("webhook_id = ?", webhook.ID).Delete(&database.Entrypoint{})
 		tx.Where("webhook_id = ?", webhook.ID).Delete(&database.Target{})
-		tx.Where("webhook_id = ?", webhook.ID).Delete(&database.Event{})
 		tx.Delete(&webhook)
 
 		if err := tx.Commit().Error; err != nil {