diff --git a/rule/file-header.go b/rule/file-header.go
index a204833..17fd9ff 100644
--- a/rule/file-header.go
+++ b/rule/file-header.go
@@ -1,6 +1,7 @@
 package rule
 
 import (
+	"fmt"
 	"regexp"
 
 	"github.com/mgechev/revive/lint"