diff --git a/tests/reverse/longname_perf_test.go b/tests/reverse/longname_perf_test.go
new file mode 100644
index 0000000..43acd25
--- /dev/null
+++ b/tests/reverse/longname_perf_test.go
@@ -0,0 +1,73 @@
+package reverse_test
+
+import (
+	"bytes"
+	"fmt"
+	"os"
+	"testing"
+
+	"github.com/rfjakob/gocryptfs/tests/test_helpers"
+)
+
+var dirA, dirB, x240 string
+
+func TestMain(m *testing.M) {
+	x240 = string(bytes.Repeat([]byte("x"), 240))
+	dirA = test_helpers.TmpDir + "/a"
+	dirB = test_helpers.TmpDir + "/b"
+	os.Mkdir(dirA, 0700)
+	os.Mkdir(dirB, 0700)
+	generateFiles(dirA)
+	test_helpers.MountOrExit(dirA, dirB, "-zerokey", "-reverse")
+	r := m.Run()
+	test_helpers.UnmountPanic(dirB)
+	os.RemoveAll(test_helpers.TmpDir)
+	os.Exit(r)
+}
+
+func genName(i int) string {
+	return fmt.Sprintf("%04d.%s", i, x240)
+}
+
+// Create 10000 files with long names
+func generateFiles(dir string) {
+	for i := 0; i < 100000; i++ {
+		n := genName(i)
+		f, err := os.Create(dir + "/" + n)
+		if err != nil {
+			panic(err)
+		}
+		f.Close()
+	}
+}
+
+func TestLongnameStat(t *testing.T) {
+	_, err := os.Stat(dirA + "/" + genName(0))
+	if err != nil {
+		t.Error(err)
+	}
+	_, err = os.Stat(dirA + "/" + genName(9999))
+	if err != nil {
+		t.Error(err)
+	}
+}
+
+func BenchmarkLongnameStat(b *testing.B) {
+	dirFd, err := os.Open(dirB)
+	if err != nil {
+		b.Fatal(err)
+	}
+	encryptedNames, err := dirFd.Readdirnames(-1)
+	if err != nil {
+		b.Fatal(err)
+	}
+	l := len(encryptedNames)
+	dirFd.Close()
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		_, err := os.Stat(dirB + "/" + encryptedNames[i%l])
+		if err != nil {
+			b.Fatal(err)
+		}
+	}
+}
diff --git a/tests/test_helpers/helpers.go b/tests/test_helpers/helpers.go
index bad5675..7e1f4e8 100644
--- a/tests/test_helpers/helpers.go
+++ b/tests/test_helpers/helpers.go
@@ -15,13 +15,18 @@ import (
 	"github.com/rfjakob/gocryptfs/internal/nametransform"
 )
 
+// TmpDir will be created inside this directory
 const testParentDir = "/tmp/gocryptfs-test-parent"
 const GocryptfsBinary = "../../gocryptfs"
 
-// "go test" runs package tests in parallel! We must create a unique TmpDir on
-// startup or the tests will interfere horribly
+// "go test" runs package tests in parallel! We create a unique TmpDir in
+// init() so the tests do not interfere.
 var TmpDir string
+
+// TmpDir + "/default-plain"
 var DefaultPlainDir string
+
+// TmpDir + "/default-cipher"
 var DefaultCipherDir string
 
 func init() {
@@ -77,7 +82,7 @@ func ResetTmpDir(plaintextNames bool) {
 }
 
 // InitFS calls "gocryptfs -init" on a new directory in TmpDir, passing
-// "extraArgs" in addition to practical defaults.
+// "extraArgs" in addition to useful defaults.
 //
 // The returned cipherdir has NO trailing slash.
 func InitFS(t *testing.T, extraArgs ...string) string {
@@ -128,7 +133,7 @@ func Mount(c string, p string, showOutput bool, extraArgs ...string) error {
 	return cmd.Run()
 }
 
-// MountOrExit calls mount() and exits on failure.
+// MountOrExit calls Mount() and exits on failure.
 func MountOrExit(c string, p string, extraArgs ...string) {
 	err := Mount(c, p, true, extraArgs...)
 	if err != nil {
@@ -137,7 +142,7 @@ func MountOrExit(c string, p string, extraArgs ...string) {
 	}
 }
 
-// MountOrFatal calls mount() and calls t.Fatal() on failure.
+// MountOrFatal calls Mount() and calls t.Fatal() on failure.
 func MountOrFatal(t *testing.T, c string, p string, extraArgs ...string) {
 	err := Mount(c, p, true, extraArgs...)
 	if err != nil {