diff --git a/query.go b/query.go
index 12e87f3..6910013 100644
--- a/query.go
+++ b/query.go
@@ -148,6 +148,11 @@ func (a *NodeNavigator) MoveToChild() bool {
 }
 
 func (a *NodeNavigator) MoveToFirst() bool {
+	// Already on the first sibling. xmlquery and htmlquery return false
+	// here so a caller can tell the navigator did not move.
+	if a.cur.PrevSibling == nil {
+		return false
+	}
 	for n := a.cur.PrevSibling; n != nil; n = n.PrevSibling {
 		a.cur = n
 	}
diff --git a/query_test.go b/query_test.go
index c56bd0a..d6d8f9e 100644
--- a/query_test.go
+++ b/query_test.go
@@ -22,6 +22,23 @@ func BenchmarkDisableSelectorCache(b *testing.B) {
 	}
 }
 
+func TestMoveToFirst(t *testing.T) {
+	doc, err := parseString(`{"a":1,"b":2}`)
+	require.NoError(t, err)
+
+	nav := CreateXPathNavigator(doc)
+	require.True(t, nav.MoveToChild())
+	require.Equal(t, "a", nav.Current().Data)
+	// Already on the first sibling. The move did not happen.
+	require.False(t, nav.MoveToFirst())
+	require.Equal(t, "a", nav.Current().Data)
+
+	require.True(t, nav.MoveToNext())
+	require.Equal(t, "b", nav.Current().Data)
+	require.True(t, nav.MoveToFirst())
+	require.Equal(t, "a", nav.Current().Data)
+}
+
 func TestNavigator(t *testing.T) {
 	s := `{
 		"name":"John",