diff --git a/hash.c b/hash.c
index b7e2c66849..bae417c642 100644
--- a/hash.c
+++ b/hash.c
@@ -177,7 +177,39 @@ static const struct st_hash_type objhash = {
     rb_any_hash,
 };
 
-#define identhash st_hashtype_num
+#define rb_ident_cmp st_numcmp
+
+static st_index_t
+rb_ident_hash(st_data_t n)
+{
+    /*
+     * This hash function is lightly-tuned for Ruby.  Further tuning
+     * should be possible.  Notes:
+     *
+     * - (n >> 3) alone is great for heap objects and OK for fixnum,
+     *   however symbols perform poorly.
+     * - (n >> (RUBY_SPECIAL_SHIFT+3)) was added to make symbols hash well,
+     *   n.b.: +3 to remove ID scope, +1 worked well initially, too
+     * - (n << 3) was finally added to avoid losing bits for fixnums
+     * - avoid expensive modulo instructions, it is currently only
+     *   shifts and bitmask operations.
+     * - flonum (on 64-bit) is pathologically bad, mix the actual
+     *   float value in, but do not use the float value as-is since
+     *   many integers get interpreted as 2.0 or -2.0 [Bug #10761]
+     */
+#ifdef USE_FLONUM /* RUBY */
+    if (FLONUM_P(n)) {
+	n ^= (st_data_t)rb_float_value(n);
+    }
+#endif
+
+    return (st_index_t)((n>>(RUBY_SPECIAL_SHIFT+3)|(n<<3)) ^ (n>>3));
+}
+
+static const struct st_hash_type identhash = {
+    rb_ident_cmp,
+    rb_ident_hash,
+};
 
 typedef int st_foreach_func(st_data_t, st_data_t, st_data_t);
 
@@ -2509,6 +2541,14 @@ rb_hash_compare_by_id_p(VALUE hash)
     return Qfalse;
 }
 
+VALUE
+rb_ident_hash_new(void)
+{
+    VALUE hash = rb_hash_new();
+    RHASH(hash)->ntbl = st_init_table(&identhash);
+    return hash;
+}
+
 static int
 any_p_i(VALUE key, VALUE value, VALUE arg)
 {
diff --git a/internal.h b/internal.h
index e7880f0177..f52a3b1c32 100644
--- a/internal.h
+++ b/internal.h
@@ -701,6 +701,7 @@ struct st_table *rb_hash_tbl_raw(VALUE hash);
 VALUE rb_hash_has_key(VALUE hash, VALUE key);
 VALUE rb_hash_set_default_proc(VALUE hash, VALUE proc);
 long rb_objid_hash(st_index_t index);
+VALUE rb_ident_hash_new(void);
 
 #define RHASH_TBL_RAW(h) rb_hash_tbl_raw(h)
 VALUE rb_hash_keys(VALUE hash);
@@ -952,9 +953,6 @@ extern int ruby_enable_coredump;
 int rb_get_next_signal(void);
 int rb_sigaltstack_size(void);
 
-/* st.c */
-extern const struct st_hash_type st_hashtype_num;
-
 /* strftime.c */
 #ifdef RUBY_ENCODING_H
 size_t rb_strftime_timespec(char *s, size_t maxsize, const char *format, rb_encoding *enc,
diff --git a/st.c b/st.c
index e630c1ec48..e238062336 100644
--- a/st.c
+++ b/st.c
@@ -1750,26 +1750,6 @@ st_numcmp(st_data_t x, st_data_t y)
 st_index_t
 st_numhash(st_data_t n)
 {
-    /*
-     * This hash function is lightly-tuned for Ruby.  Further tuning
-     * should be possible.  Notes:
-     *
-     * - (n >> 3) alone is great for heap objects and OK for fixnum,
-     *   however symbols perform poorly.
-     * - (n >> (RUBY_SPECIAL_SHIFT+3)) was added to make symbols hash well,
-     *   n.b.: +3 to remove ID scope, +1 worked well initially, too
-     * - (n << 3) was finally added to avoid losing bits for fixnums
-     * - avoid expensive modulo instructions, it is currently only
-     *   shifts and bitmask operations.
-     * - flonum (on 64-bit) is pathologically bad, mix the actual
-     *   float value in, but do not use the float value as-is since
-     *   many integers get interpreted as 2.0 or -2.0 [Bug #10761]
-     */
-#ifdef USE_FLONUM /* RUBY */
-    if (FLONUM_P(n)) {
-	n ^= (st_data_t)rb_float_value(n);
-    }
-#endif
-
-    return (st_index_t)((n>>(RUBY_SPECIAL_SHIFT+3)|(n<<3)) ^ (n>>3));
+    enum {s1 = 11, s2 = 3};
+    return (st_index_t)((n>>s1|(n<<s2)) ^ (n>>s2));
 }
diff --git a/thread.c b/thread.c
index 5d8ac7eb04..37c7252620 100644
--- a/thread.c
+++ b/thread.c
@@ -4675,14 +4675,6 @@ rb_thread_shield_destroy(VALUE self)
     return rb_thread_shield_waiting(self) > 0 ? Qtrue : Qfalse;
 }
 
-static VALUE
-ident_hash_new(void)
-{
-    VALUE hash = rb_hash_new();
-    rb_hash_tbl_raw(hash)->type = &st_hashtype_num;
-    return hash;
-}
-
 static VALUE
 threadptr_recursive_hash(rb_thread_t *th)
 {
@@ -4710,7 +4702,7 @@ recursive_list_access(VALUE sym)
     VALUE hash = threadptr_recursive_hash(th);
     VALUE list;
     if (NIL_P(hash) || !RB_TYPE_P(hash, T_HASH)) {
-	hash = ident_hash_new();
+	hash = rb_ident_hash_new();
 	threadptr_recursive_hash_set(th, hash);
 	list = Qnil;
     }
@@ -4718,7 +4710,7 @@ recursive_list_access(VALUE sym)
 	list = rb_hash_aref(hash, sym);
     }
     if (NIL_P(list) || !RB_TYPE_P(list, T_HASH)) {
-	list = ident_hash_new();
+	list = rb_ident_hash_new();
 	rb_hash_aset(hash, sym, list);
     }
     return list;