diff --git a/libs/filer/filer.go b/libs/filer/filer.go
index a748e1fd4..4d6facbe5 100644
--- a/libs/filer/filer.go
+++ b/libs/filer/filer.go
@@ -18,7 +18,7 @@ type WriteMode int
 const writeModePerm = WriteMode(fs.ModePerm)
 
 const (
-	OverwriteIfExists WriteMode = writeModePerm + 1<<iota
+	OverwriteIfExists WriteMode = (writeModePerm + 1) << iota
 	CreateParentDirectories
 )
 
diff --git a/libs/filer/filer_test.go b/libs/filer/filer_test.go
index 187eb0f00..bacea730b 100644
--- a/libs/filer/filer_test.go
+++ b/libs/filer/filer_test.go
@@ -8,4 +8,5 @@ import (
 
 func TestWriteMode(t *testing.T) {
 	assert.Equal(t, 512, int(OverwriteIfExists))
+	assert.Equal(t, 1024, int(CreateParentDirectories))
 }