diff --git a/treetrie.c b/treetrie.c
index cd25e9e..22852e4 100644
--- a/treetrie.c
+++ b/treetrie.c
@@ -8,17 +8,50 @@
 #include "treetrie.h"
 #include "fasthash.h"
 
+/* /\* Customized special-purpose fasthash variation *\/ */
+/* #define mix(h) ({					\ */
+/* 			(h) ^= (h) >> 23;		\ */
+/* 			(h) *= 0x2127599bf4325c37ULL;	\ */
+/* 			(h) ^= (h) >> 47; }) */
+/* static inline uint64_t fasthash_4_ints(uint32_t v1, uint32_t v2, uint32_t v3, uint32_t v4) { */
+/*   const uint64_t    m = 0x880355f21e6d1965ULL; */
+/*   uint64_t h = (16 * m); */
+/*   uint64_t v; */
+/*   v = (((uint64_t) v2) << 32) | v1; */
+/*   h ^= mix(v); */
+/*   h *= m; */
+/*   v = (((uint64_t) v4) << 32) | v3; */
+/*   h ^= mix(v); */
+/*   h *= m; */
+/*   return mix(h); */
+/* } */
+
 static inline tt_hash_t hash(uint32_t tag,
 			     uint32_t index,
 			     tt_node_idx_t a,
 			     tt_node_idx_t b)
 {
-  uint32_t keyblock[4] = { tag,
-			   index,
-			   a,
-			   b };
-  assert(sizeof(keyblock) == 4 * sizeof(uint32_t));
-  return (tt_hash_t) fasthash32(keyblock, sizeof(keyblock), 0);
+  /* uint64_t x = fasthash_4_ints(tag, index, a, b); */
+  /* return x - (x >> 32); */
+
+  /* uint32_t keyblock[4] = { tag, */
+  /* 			   index, */
+  /* 			   a, */
+  /* 			   b }; */
+  /* assert(sizeof(keyblock) == 4 * sizeof(uint32_t)); */
+  /* return (tt_hash_t) fasthash32(keyblock, sizeof(keyblock), 0); */
+
+  /* uint64_t x = tag; */
+  /* x = (x << 8) ^ index; */
+  /* x = (x << 8) ^ a; */
+  /* x = (x << 8) ^ b; */
+  /* return x - (x >> 32); */
+
+  uint64_t x = tag;
+  x ^= index * 11;
+  x ^= a * 11;
+  x ^= b * 11;
+  return x - (x >> 32);
 }
 
 inline tt_hash_t tt_hash_node(tt_arena_t *a, tt_node_idx_t i) {