diff --git a/data_test.go b/data_test.go
index 81ade81..ea02471 100644
--- a/data_test.go
+++ b/data_test.go
@@ -9,6 +9,8 @@ import (
 	"github.com/stretchr/testify/assert"
 )
 
+// testFS exposes a filesystem rooted at ".", with testdata/ as a real directory entry.
+//
 //go:embed testdata
 var testFS embed.FS
 
@@ -46,6 +48,14 @@ func TestData_ReadString_Good(t *testing.T) {
 	assert.Equal(t, "hello from testdata\n", r.Value.(string))
 }
 
+func TestData_ReadString_RootMount_Good(t *testing.T) {
+	c := New().Value.(*Core)
+	c.Data().New(Options{{Key: "name", Value: "app"}, {Key: "source", Value: testFS}, {Key: "path", Value: "."}})
+	r := c.Data().ReadString("app/testdata/test.txt")
+	assert.True(t, r.OK)
+	assert.Equal(t, "hello from testdata\n", r.Value.(string))
+}
+
 func TestData_ReadString_Bad(t *testing.T) {
 	c := New().Value.(*Core)
 	r := c.Data().ReadString("nonexistent/file.txt")
diff --git a/embed_test.go b/embed_test.go
index 99fc7cd..b721cbb 100644
--- a/embed_test.go
+++ b/embed_test.go
@@ -39,6 +39,13 @@ func TestEmbed_ReadString_Good(t *testing.T) {
 	assert.Equal(t, "hello from testdata\n", r.Value.(string))
 }
 
+func TestEmbed_ReadString_RootMount_Good(t *testing.T) {
+	emb := Mount(testFS, ".").Value.(*Embed)
+	r := emb.ReadString("testdata/test.txt")
+	assert.True(t, r.OK)
+	assert.Equal(t, "hello from testdata\n", r.Value.(string))
+}
+
 func TestEmbed_Open_Good(t *testing.T) {
 	emb := Mount(testFS, "testdata").Value.(*Embed)
 	r := emb.Open("test.txt")