diff --git a/main.go b/main.go
index 3e867b8..dc374bc 100644
--- a/main.go
+++ b/main.go
@@ -25,6 +25,9 @@ func init() {
 }
 
 func main() {
+	if version == "" {
+		version = "unknown"
+	}
 	log.Println("SpaceAPId version", version)
 
 	flag.Parse()