diff --git a/modules/structs/attachment.go b/modules/structs/attachment.go
index 954956f32..7becd9433 100644
--- a/modules/structs/attachment.go
+++ b/modules/structs/attachment.go
@@ -3,6 +3,7 @@
 // license that can be found in the LICENSE file.
 
 package structs // import "code.gitea.io/gitea/modules/structs"
+
 import (
 	"time"
 )
diff --git a/modules/structs/go.mod b/modules/structs/go.mod
new file mode 100644
index 000000000..96826f2f0
--- /dev/null
+++ b/modules/structs/go.mod
@@ -0,0 +1,3 @@
+module code.gitea.io/gitea/modules/structs
+
+go 1.12