diff --git a/config/config.go b/config/config.go
index 3965f7e..776e5c9 100644
--- a/config/config.go
+++ b/config/config.go
@@ -188,6 +188,9 @@ func parseChannelRange(spec string, start, end *int) error {
 		*start = ch
 		*end = ch
 	}
+	if *start > *end {
+		return fmt.Errorf("channel start %d > end %d", *start, *end)
+	}
 	return nil
 }