diff --git a/samples/memfs/memfs_test.go b/samples/memfs/memfs_test.go
index 9c10b93..d9e821e 100644
--- a/samples/memfs/memfs_test.go
+++ b/samples/memfs/memfs_test.go
@@ -540,7 +540,27 @@ func (t *MemFSTest) ModifyExistingFile_InSubDir() {
 }
 
 func (t *MemFSTest) UnlinkFile_Exists() {
-	AssertTrue(false, "TODO")
+	var err error
+
+	// Write a file.
+	fileName := path.Join(t.mfs.Dir(), "foo")
+	err = ioutil.WriteFile(fileName, []byte("Jello, world!"), 0600)
+	AssertEq(nil, err)
+
+	// Unlink it.
+	err = os.Remove(fileName)
+	AssertEq(nil, err)
+
+	// Statting it should fail.
+	_, err = os.Stat(fileName)
+
+	AssertNe(nil, err)
+	ExpectThat(err, Error(HasSubstr("no such file")))
+
+	// Nothing should be in the directory.
+	entries, err := ioutil.ReadDir(t.mfs.Dir())
+	AssertEq(nil, err)
+	ExpectThat(entries, ElementsAre())
 }
 
 func (t *MemFSTest) UnlinkFile_NotAFile() {