diff --git a/internal/nametransform/diriv_cache.go b/internal/nametransform/diriv_cache.go
new file mode 100644
index 0000000..c6f2ca9
--- /dev/null
+++ b/internal/nametransform/diriv_cache.go
@@ -0,0 +1,43 @@
+package nametransform
+
+import "sync"
+
+// A simple one-entry DirIV cache
+type dirIVCache struct {
+	// Invalidated?
+	cleared bool
+	// The DirIV
+	iv []byte
+	// Directory the DirIV belongs to
+	dir string
+	// Ecrypted version of "dir"
+	translatedDir string
+	// Synchronisation
+	lock sync.RWMutex
+}
+
+// lookup - fetch entry for "dir" from the cache
+func (c *dirIVCache) lookup(dir string) (bool, []byte, string) {
+	c.lock.RLock()
+	defer c.lock.RUnlock()
+	if !c.cleared && c.dir == dir {
+		return true, c.iv, c.translatedDir
+	}
+	return false, nil, ""
+}
+
+// store - write entry for "dir" into the caches
+func (c *dirIVCache) store(dir string, iv []byte, translatedDir string) {
+	c.lock.Lock()
+	defer c.lock.Unlock()
+	c.cleared = false
+	c.iv = iv
+	c.dir = dir
+	c.translatedDir = translatedDir
+}
+
+func (c *dirIVCache) Clear() {
+	c.lock.Lock()
+	defer c.lock.Unlock()
+	c.cleared = true
+}
diff --git a/internal/nametransform/names_diriv.go b/internal/nametransform/names_diriv.go
index 61e5bf0..94c41c8 100644
--- a/internal/nametransform/names_diriv.go
+++ b/internal/nametransform/names_diriv.go
@@ -6,7 +6,6 @@ import (
 	"os"
 	"path/filepath"
 	"strings"
-	"sync"
 
 	"github.com/rfjakob/gocryptfs/internal/cryptocore"
 	"github.com/rfjakob/gocryptfs/internal/toggledlog"
@@ -20,46 +19,6 @@ const (
 	DirIVFilename = "gocryptfs.diriv"
 )
 
-// A simple one-entry DirIV cache
-type dirIVCache struct {
-	// Invalidated?
-	cleared bool
-	// The DirIV
-	iv []byte
-	// Directory the DirIV belongs to
-	dir string
-	// Ecrypted version of "dir"
-	translatedDir string
-	// Synchronisation
-	lock sync.RWMutex
-}
-
-// lookup - fetch entry for "dir" from the cache
-func (c *dirIVCache) lookup(dir string) (bool, []byte, string) {
-	c.lock.RLock()
-	defer c.lock.RUnlock()
-	if !c.cleared && c.dir == dir {
-		return true, c.iv, c.translatedDir
-	}
-	return false, nil, ""
-}
-
-// store - write entry for "dir" into the caches
-func (c *dirIVCache) store(dir string, iv []byte, translatedDir string) {
-	c.lock.Lock()
-	defer c.lock.Unlock()
-	c.cleared = false
-	c.iv = iv
-	c.dir = dir
-	c.translatedDir = translatedDir
-}
-
-func (c *dirIVCache) Clear() {
-	c.lock.Lock()
-	defer c.lock.Unlock()
-	c.cleared = true
-}
-
 // readDirIV - read the "gocryptfs.diriv" file from "dir" (absolute ciphertext path)
 func (be *NameTransform) ReadDirIV(dir string) (iv []byte, readErr error) {
 	ivfile := filepath.Join(dir, DirIVFilename)