diff --git a/treetrie.h b/treetrie.h
index e3b804e..1265905 100644
--- a/treetrie.h
+++ b/treetrie.h
@@ -29,7 +29,7 @@ typedef enum tt_special_idx_t {
 #define TT_STYLE_HIDE_DETAILS	0x00000002
 
 typedef uint32_t tt_node_idx_t; /* N.B. tt_special_idx_t; and 0 is reserved. */
-typedef uint32_t tt_node_ptr_t; /* An index shifted left 2 with tag or'd in low bits */
+typedef uint32_t tt_node_ptr_t; /* An index shifted left 3 with tag or'd in low bits */
 
 #define TT_NO_IDX		((tt_node_idx_t) (0))
 #define TT_NO_PTR		((tt_node_ptr_t) (0))