--- a/pkg/imports/bn.go	Thu May 23 15:33:23 2019 +0200
+++ b/pkg/imports/bn.go	Thu May 23 15:33:56 2019 +0200
@@ -146,14 +146,6 @@
 	return &m[1], &m[2]
 }
 
-func revisitingTime(s string) int {
-	v, err := strconv.Atoi(s)
-	if err != nil {
-		v = 0
-	}
-	return v
-}
-
 // Do executes the actual bottleneck import.
 func (bn *Bottleneck) Do(
 	ctx context.Context,
@@ -275,6 +267,17 @@
 
 	rb, lb := splitRBLB(bn.Rb_lb)
 
+	var revisitingTime *int
+	if bn.Revisiting_time != nil {
+		i, err := strconv.Atoi(*bn.Revisiting_time)
+		if err != nil {
+			feedback.Warn("Cannot convert '%s' to number of months",
+				*bn.Revisiting_time)
+		} else {
+			revisitingTime = &i
+		}
+	}
+
 	var limiting, country string
 
 	if bn.Limiting_factor != nil {
@@ -297,7 +300,7 @@
 		rb,
 		lb,
 		country,
-		revisitingTime(bn.Revisiting_time),
+		revisitingTime,
 		limiting,
 		bn.Date_Info,
 		bn.Source,