diff --git a/lib/resty/wasmx/shm.lua b/lib/resty/wasmx/shm.lua
index e0da2e6da..d41485c81 100644
--- a/lib/resty/wasmx/shm.lua
+++ b/lib/resty/wasmx/shm.lua
@@ -11,6 +11,7 @@ local tonumber = tonumber
 local min = math.min
 local new_tab = table.new
 local insert = table.insert
+local sort = table.sort
 local str_fmt = string.format
 local ffi_cast = ffi.cast
 local ffi_fill = ffi.fill
@@ -58,6 +59,11 @@ ffi.cdef [[
         NGX_WA_METRIC_HISTOGRAM,
     } ngx_wa_metric_type_e;
 
+    typedef enum {
+        NGX_WA_HISTOGRAM_LOG2,
+        NGX_WA_HISTOGRAM_CUSTOM,
+    } ngx_wa_histogram_type_e;
+
     typedef struct {
         ngx_uint_t                   value;
         ngx_msec_t                   last_update;
@@ -69,6 +75,7 @@ ffi.cdef [[
     } ngx_wa_metrics_bin_t;
 
     typedef struct {
+        ngx_wa_histogram_type_e      h_type;
         uint8_t                      n_bins;
         uint64_t                     sum;
         ngx_wa_metrics_bin_t         bins[];
@@ -109,6 +116,8 @@ ffi.cdef [[
 
     ngx_int_t ngx_wa_ffi_shm_metric_define(ngx_str_t *name,
                                            ngx_wa_metric_type_e type,
+                                           uint32_t *bins,
+                                           uint16_t n_bins,
                                            uint32_t *metric_id);
     ngx_int_t ngx_wa_ffi_shm_metric_increment(uint32_t metric_id,
                                               ngx_uint_t value);
@@ -124,11 +133,13 @@ ffi.cdef [[
 
     ngx_int_t ngx_wa_ffi_shm_metrics_one_slot_size();
     ngx_int_t ngx_wa_ffi_shm_metrics_histogram_max_size();
+    ngx_int_t ngx_wa_ffi_shm_metrics_histogram_max_bins();
 ]]
 
 
 local WASM_SHM_KEY = {}
 local DEFAULT_KEYS_PAGE_SIZE = 500
+local MAX_HISTOGRAM_BINS = C.ngx_wa_ffi_shm_metrics_histogram_max_bins()
 
 
 local _M = setmetatable({}, {
@@ -341,7 +352,7 @@ local function shm_kv_set(zone, key, value, cas)
 end
 
 
-local function metrics_define(zone, name, metric_type)
+local function metrics_define(zone, name, metric_type, opts)
     if type(name) ~= "string" or name == "" then
         error("name must be a non-empty string", 2)
     end
@@ -355,12 +366,36 @@ local function metrics_define(zone, name, metric_type)
         error(err, 2)
     end
 
+    local cbins = nil
+    local n_bins = 0
+
+    if opts ~= nil then
+        if type(opts) ~= "table" then
+            error("opts must be a table", 2)
+        end
+
+        if opts.bins ~= nil then
+            if type(opts.bins) ~= "table" then
+                error("opts.bins must be a table", 2)
+            end
+
+            if #opts.bins > MAX_HISTOGRAM_BINS then
+                local err = "opts.bins must have up to %d numbers"
+                error(str_fmt(err, MAX_HISTOGRAM_BINS), 2)
+            end
+
+            sort(opts.bins)
+            cbins = ffi_new("uint32_t[?]", #opts.bins, opts.bins)
+            n_bins = #opts.bins
+        end
+    end
+
     name = "lua." .. name
 
     local cname = ffi_new("ngx_str_t", { data = name, len = #name })
     local m_id = ffi_new("uint32_t [1]")
 
-    local rc = C.ngx_wa_ffi_shm_metric_define(cname, metric_type, m_id)
+    local rc = C.ngx_wa_ffi_shm_metric_define(cname, metric_type, cbins, n_bins, m_id)
     if rc == FFI_ERROR then
         return nil, "no memory"
     end
diff --git a/src/common/debug/ngx_wasm_debug_module.c b/src/common/debug/ngx_wasm_debug_module.c
index ebade40be..ba93da253 100644
--- a/src/common/debug/ngx_wasm_debug_module.c
+++ b/src/common/debug/ngx_wasm_debug_module.c
@@ -60,6 +60,7 @@ ngx_wasm_debug_init(ngx_cycle_t *cycle)
         ngx_wa_metrics_define(ngx_wasmx_metrics(cycle),
                               &metric_name,
                               NGX_WA_METRIC_COUNTER,
+                              NULL, 0,
                               &mid) == NGX_BUSY
     );
 
@@ -68,6 +69,7 @@ ngx_wasm_debug_init(ngx_cycle_t *cycle)
         ngx_wa_metrics_define(ngx_wasmx_metrics(cycle),
                               &metric_name,
                               100,
+                              NULL, 0,
                               &mid) == NGX_ABORT
     );
 
diff --git a/src/common/lua/ngx_wasm_lua_ffi.c b/src/common/lua/ngx_wasm_lua_ffi.c
index 35a1657df..12cb5b6b7 100644
--- a/src/common/lua/ngx_wasm_lua_ffi.c
+++ b/src/common/lua/ngx_wasm_lua_ffi.c
@@ -409,12 +409,12 @@ ngx_wa_ffi_shm_kv_set(ngx_wa_shm_t *shm, ngx_str_t *k, ngx_str_t *v,
 
 ngx_int_t
 ngx_wa_ffi_shm_metric_define(ngx_str_t *name, ngx_wa_metric_type_e type,
-    uint32_t *metric_id)
+    uint32_t *bins, uint16_t n_bins, uint32_t *metric_id)
 {
     ngx_int_t          rc;
     ngx_wa_metrics_t  *metrics = ngx_wasmx_metrics((ngx_cycle_t *) ngx_cycle);
 
-    rc = ngx_wa_metrics_define(metrics, name, type, metric_id);
+    rc = ngx_wa_metrics_define(metrics, name, type, bins, n_bins, metric_id);
     if (rc != NGX_OK) {
         return rc;
     }
diff --git a/src/common/lua/ngx_wasm_lua_ffi.h b/src/common/lua/ngx_wasm_lua_ffi.h
index 87dc42881..69248e0ef 100644
--- a/src/common/lua/ngx_wasm_lua_ffi.h
+++ b/src/common/lua/ngx_wasm_lua_ffi.h
@@ -58,7 +58,8 @@ ngx_int_t ngx_wa_ffi_shm_kv_set(ngx_wa_shm_t *shm, ngx_str_t *k,
     ngx_str_t *v, uint32_t cas, unsigned *written);
 
 ngx_int_t ngx_wa_ffi_shm_metric_define(ngx_str_t *name,
-    ngx_wa_metric_type_e type, uint32_t *metric_id);
+    ngx_wa_metric_type_e type, uint32_t *bins, uint16_t n_bins,
+    uint32_t *metric_id);
 ngx_int_t ngx_wa_ffi_shm_metric_increment(uint32_t metric_id, ngx_uint_t value);
 ngx_int_t ngx_wa_ffi_shm_metric_record(uint32_t metric_id, ngx_uint_t value);
 ngx_int_t ngx_wa_ffi_shm_metric_get(uint32_t metric_id, ngx_str_t *name,
@@ -93,4 +94,11 @@ ngx_wa_ffi_shm_metrics_histogram_max_size()
 }
 
 
+ngx_int_t
+ngx_wa_ffi_shm_metrics_histogram_max_bins()
+{
+    return NGX_WA_METRICS_BINS_MAX;
+}
+
+
 #endif /* _NGX_WASM_LUA_FFI_H_INCLUDED_ */
diff --git a/src/common/metrics/ngx_wa_histogram.c b/src/common/metrics/ngx_wa_histogram.c
index 3ce123215..e708d3247 100644
--- a/src/common/metrics/ngx_wa_histogram.c
+++ b/src/common/metrics/ngx_wa_histogram.c
@@ -77,7 +77,28 @@ histogram_grow(ngx_wa_metrics_t *metrics, ngx_wa_metrics_histogram_t *h,
 
 
 static ngx_wa_metrics_bin_t *
-histogram_bin(ngx_wa_metrics_t *metrics, ngx_wa_metrics_histogram_t *h,
+histogram_custom_bin(ngx_wa_metrics_t *metrics, ngx_wa_metrics_histogram_t *h,
+    ngx_uint_t n)
+{
+    size_t                 i = 0;
+    ngx_wa_metrics_bin_t  *b;
+
+    for (i = 0; i < h->n_bins; i++) {
+        b = &h->bins[i];
+
+        if (b->upper_bound >= n) {
+            return b;
+        }
+    }
+
+    ngx_wa_assert(0);
+
+    return NULL;
+}
+
+
+static ngx_wa_metrics_bin_t *
+histogram_log2_bin(ngx_wa_metrics_t *metrics, ngx_wa_metrics_histogram_t *h,
     ngx_uint_t n, ngx_wa_metrics_histogram_t **out)
 {
     size_t                 i, j = 0;
@@ -160,13 +181,19 @@ histogram_log(ngx_wa_metrics_t *metrics, ngx_wa_metric_t *m, uint32_t mid)
 
 
 ngx_int_t
-ngx_wa_metrics_histogram_add_locked(ngx_wa_metrics_t *metrics,
-    ngx_wa_metric_t *m)
+ngx_wa_metrics_histogram_add_locked(ngx_wa_metrics_t *metrics, uint32_t *bins,
+    uint16_t cn_bins, ngx_wa_metric_t *m)
 {
     size_t                        i;
-    static uint16_t               n_bins = NGX_WA_METRICS_BINS_INIT;
+    uint16_t                      j = 0, n_bins = NGX_WA_METRICS_BINS_INIT;
+    ngx_wa_histogram_type_e       h_type = NGX_WA_HISTOGRAM_LOG2;
     ngx_wa_metrics_histogram_t  **h;
 
+    if (bins) {
+        n_bins = cn_bins + 1;
+        h_type = NGX_WA_HISTOGRAM_CUSTOM;
+    }
+
     for (i = 0; i < metrics->workers; i++) {
         h = &m->slots[i].histogram;
         *h = ngx_slab_calloc_locked(metrics->shm->shpool,
@@ -177,7 +204,16 @@ ngx_wa_metrics_histogram_add_locked(ngx_wa_metrics_t *metrics,
         }
 
         (*h)->n_bins = n_bins;
-        (*h)->bins[0].upper_bound = NGX_MAX_UINT32_VALUE;
+        (*h)->h_type = h_type;
+
+        if (bins) {
+            /* user-defined set of bins */
+            for (/* void */; j < n_bins - 1; j++) {
+                (*h)->bins[j].upper_bound = bins[j];
+            }
+        }
+
+        (*h)->bins[j].upper_bound = NGX_MAX_UINT32_VALUE;
     }
 
     return NGX_OK;
@@ -199,13 +235,24 @@ ngx_int_t
 ngx_wa_metrics_histogram_record(ngx_wa_metrics_t *metrics, ngx_wa_metric_t *m,
     ngx_uint_t slot, uint32_t mid, ngx_uint_t n)
 {
-    ngx_wa_metrics_bin_t        *b;
     ngx_wa_metrics_histogram_t  *h;
+    ngx_wa_metrics_bin_t        *b;
 
     h = m->slots[slot].histogram;
     h->sum += n;
 
-    b = histogram_bin(metrics, h, n, &m->slots[slot].histogram);
+    switch (h->h_type) {
+    case NGX_WA_HISTOGRAM_LOG2:
+        b = histogram_log2_bin(metrics, h, n, &m->slots[slot].histogram);
+        break;
+    case NGX_WA_HISTOGRAM_CUSTOM:
+        b = histogram_custom_bin(metrics, h, n);
+        break;
+    default:
+        ngx_wa_assert(0);
+        return NGX_ERROR;
+    }
+
     b->count += 1;
 
 #if (NGX_DEBUG)
@@ -230,7 +277,20 @@ ngx_wa_metrics_histogram_get(ngx_wa_metrics_t *metrics, ngx_wa_metric_t *m,
 
         for (j = 0; j < h->n_bins; j++) {
             b = &h->bins[j];
-            out_b = histogram_bin(metrics, out, b->upper_bound, NULL);
+
+            switch (h->h_type) {
+            case NGX_WA_HISTOGRAM_LOG2:
+                out_b = histogram_log2_bin(metrics, out, b->upper_bound, NULL);
+                break;
+            case NGX_WA_HISTOGRAM_CUSTOM:
+                out_b = &out->bins[j];
+                out_b->upper_bound = b->upper_bound;
+                break;
+            default:
+                ngx_wa_assert(0);
+                return;
+            }
+
             out_b->count += b->count;
 
             if (b->upper_bound == NGX_MAX_UINT32_VALUE) {
diff --git a/src/common/metrics/ngx_wa_metrics.c b/src/common/metrics/ngx_wa_metrics.c
index 3bcdc0a4f..b07f1aa76 100644
--- a/src/common/metrics/ngx_wa_metrics.c
+++ b/src/common/metrics/ngx_wa_metrics.c
@@ -103,7 +103,9 @@ realloc_metrics(ngx_wa_metrics_t *metrics, ngx_rbtree_node_t *node,
     ngx_log_debug1(NGX_LOG_DEBUG_WASM, metrics->shm->log, 0,
                    "reallocating metric \"%V\"", &n->key.str);
 
-    if (ngx_wa_metrics_define(metrics, &n->key.str, m->type, &mid) != NGX_OK) {
+    if (ngx_wa_metrics_define(metrics, &n->key.str, m->type, NULL, 0, &mid)
+        != NGX_OK)
+    {
         ngx_wasm_log_error(NGX_LOG_ERR, metrics->shm->log, 0,
                            "failed redefining metric \"%V\"",
                            &n->key.str);
@@ -276,7 +278,7 @@ ngx_wa_metrics_shm_init(ngx_cycle_t *cycle)
  */
 ngx_int_t
 ngx_wa_metrics_define(ngx_wa_metrics_t *metrics, ngx_str_t *name,
-    ngx_wa_metric_type_e type, uint32_t *out)
+    ngx_wa_metric_type_e type, uint32_t *bins, uint16_t n_bins, uint32_t *out)
 {
     ssize_t           size = sizeof(ngx_wa_metric_t)
                              + sizeof(ngx_wa_metric_val_t) * metrics->workers;
@@ -316,7 +318,7 @@ ngx_wa_metrics_define(ngx_wa_metrics_t *metrics, ngx_str_t *name,
     m->type = type;
 
     if (type == NGX_WA_METRIC_HISTOGRAM) {
-        rc = ngx_wa_metrics_histogram_add_locked(metrics, m);
+        rc = ngx_wa_metrics_histogram_add_locked(metrics, bins, n_bins,  m);
         if (rc != NGX_OK) {
             goto error;
         }
diff --git a/src/common/metrics/ngx_wa_metrics.h b/src/common/metrics/ngx_wa_metrics.h
index cdfec17c6..5ebb40d25 100644
--- a/src/common/metrics/ngx_wa_metrics.h
+++ b/src/common/metrics/ngx_wa_metrics.h
@@ -29,6 +29,12 @@ typedef enum {
 } ngx_wa_metric_type_e;
 
 
+typedef enum {
+    NGX_WA_HISTOGRAM_LOG2,
+    NGX_WA_HISTOGRAM_CUSTOM,
+} ngx_wa_histogram_type_e;
+
+
 typedef struct {
     ngx_uint_t                   value;
     ngx_msec_t                   last_update;
@@ -42,6 +48,7 @@ typedef struct {
 
 
 typedef struct {
+    ngx_wa_histogram_type_e      h_type;
     uint8_t                      n_bins;
     uint64_t                     sum;
     ngx_wa_metrics_bin_t         bins[];
@@ -84,7 +91,7 @@ char *ngx_wa_metrics_init_conf(ngx_conf_t *cf);
 ngx_int_t ngx_wa_metrics_shm_init(ngx_cycle_t *cycle);
 
 ngx_int_t ngx_wa_metrics_define(ngx_wa_metrics_t *metrics, ngx_str_t *name,
-    ngx_wa_metric_type_e type, uint32_t *out);
+    ngx_wa_metric_type_e type, uint32_t *bins, uint16_t n_bins, uint32_t *out);
 ngx_int_t ngx_wa_metrics_increment(ngx_wa_metrics_t *metrics,
     uint32_t metric_id, ngx_int_t val);
 ngx_int_t ngx_wa_metrics_record(ngx_wa_metrics_t *metrics, uint32_t metric_id,
@@ -93,7 +100,7 @@ ngx_int_t ngx_wa_metrics_get(ngx_wa_metrics_t *metrics, uint32_t metric_id,
     ngx_wa_metric_t *o);
 
 ngx_int_t ngx_wa_metrics_histogram_add_locked(ngx_wa_metrics_t *metrics,
-    ngx_wa_metric_t *m);
+    uint32_t *bins, uint16_t n_bins, ngx_wa_metric_t *m);
 ngx_int_t ngx_wa_metrics_histogram_record(ngx_wa_metrics_t *metrics,
     ngx_wa_metric_t *m, ngx_uint_t slot, uint32_t mid, ngx_uint_t n);
 void ngx_wa_metrics_histogram_get(ngx_wa_metrics_t *metrics, ngx_wa_metric_t *m,
diff --git a/src/common/proxy_wasm/ngx_proxy_wasm_host.c b/src/common/proxy_wasm/ngx_proxy_wasm_host.c
index 48520bc87..d92ffddb7 100644
--- a/src/common/proxy_wasm/ngx_proxy_wasm_host.c
+++ b/src/common/proxy_wasm/ngx_proxy_wasm_host.c
@@ -1638,7 +1638,7 @@ ngx_proxy_wasm_hfuncs_define_metric(ngx_wavm_instance_t *instance,
     prefixed_name.len = ngx_sprintf(buf, "pw.%V.%V", filter_name, &name)
                         - buf;
 
-    rc = ngx_wa_metrics_define(metrics, &prefixed_name, type, id);
+    rc = ngx_wa_metrics_define(metrics, &prefixed_name, type, NULL, 0, id);
     switch (rc) {
     case NGX_ERROR:
         ngx_sprintf(trapmsg, "could not define metric \"%*s\": "
diff --git a/t/04-openresty/ffi/shm/020-metrics_define.t b/t/04-openresty/ffi/shm/020-metrics_define.t
index a6d842449..1043b8216 100644
--- a/t/04-openresty/ffi/shm/020-metrics_define.t
+++ b/t/04-openresty/ffi/shm/020-metrics_define.t
@@ -6,7 +6,7 @@ use t::TestWasmX::Lua;
 
 skip_no_openresty();
 
-plan_tests(6);
+plan_tests(7);
 run_tests();
 
 __DATA__
@@ -20,10 +20,13 @@ __DATA__
         access_by_lua_block {
             local shm = require "resty.wasmx.shm"
 
+            local bins = { 1, 3, 5, 7, 11, 13, 17 }
+
             local metrics = {
                 c1 = shm.metrics:define("c1", shm.metrics.COUNTER),
                 g1 = shm.metrics:define("g1", shm.metrics.GAUGE),
                 h1 = shm.metrics:define("h1", shm.metrics.HISTOGRAM),
+                ch1 = shm.metrics:define("ch1", shm.metrics.HISTOGRAM, { bins = bins }),
             }
 
             for _, id in pairs(metrics) do
@@ -40,6 +43,7 @@ ok
     qr/.*? \[debug\] .*? defined counter "lua.c1" with id \d+/,
     qr/.*? \[debug\] .*? defined gauge "lua.g1" with id \d+/,
     qr/.*? \[debug\] .*? defined histogram "lua.h1" with id \d+/,
+    qr/.*? \[debug\] .*? defined histogram "lua.ch1" with id \d+/,
 ]
 --- no_error_log
 [error]
@@ -66,6 +70,7 @@ err: name too long
 [crit]
 [emerg]
 [alert]
+[stub]
 
 
 
@@ -97,6 +102,7 @@ ok
 --- no_error_log
 [emerg]
 [alert]
+[stub]
 
 
 
@@ -115,14 +121,24 @@ ok
 
             _, perr = pcall(shm.metrics.define, {}, "c1", 10)
             ngx.say(perr)
+
+            _, perr = pcall(shm.metrics.define, {}, "ch1", shm.metrics.HISTOGRAM, { bins = 10 })
+            ngx.say(perr)
+
+            local bins = { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19 }
+            _, perr = pcall(shm.metrics.define, {}, "ch1", shm.metrics.HISTOGRAM, { bins = bins })
+            ngx.say(perr)
         }
     }
 --- response_body
 name must be a non-empty string
 name must be a non-empty string
 metric_type must be one of resty.wasmx.shm.metrics.COUNTER, resty.wasmx.shm.metrics.GAUGE, or resty.wasmx.shm.metrics.HISTOGRAM
+opts.bins must be a table
+opts.bins must have up to 18 numbers
 --- no_error_log
 [error]
 [crit]
 [emerg]
 [alert]
+[stub]
diff --git a/t/04-openresty/ffi/shm/022-metrics_record.t b/t/04-openresty/ffi/shm/022-metrics_record.t
index 2b8ac482d..4bc98c640 100644
--- a/t/04-openresty/ffi/shm/022-metrics_record.t
+++ b/t/04-openresty/ffi/shm/022-metrics_record.t
@@ -23,16 +23,25 @@ __DATA__
             local g1 = shm.metrics:define("g1", shm.metrics.GAUGE)
             local h1 = shm.metrics:define("h1", shm.metrics.HISTOGRAM)
 
+            local bins = { 1, 3, 5 }
+            local ch1 = shm.metrics:define("ch1", shm.metrics.HISTOGRAM, { bins = bins })
+
             assert(shm.metrics:record(g1, 10))
             assert(shm.metrics:record(h1, 100))
 
+            for i in ipairs({ 1, 2, 3, 4, 5, 6 }) do
+                assert(shm.metrics:record(ch1, i))
+            end
+
             ngx.say("g1: ", pretty.write(shm.metrics:get(g1), ""))
             ngx.say("h1: ", pretty.write(shm.metrics:get(h1), ""))
+            ngx.say("ch1: ", pretty.write(shm.metrics:get(ch1), ""))
         }
     }
 --- response_body
 g1: {type="gauge",value=10}
 h1: {sum=100,type="histogram",value={{count=1,ub=128},{count=0,ub=4294967295}}}
+ch1: {sum=21,type="histogram",value={{count=1,ub=1},{count=2,ub=3},{count=2,ub=5},{count=1,ub=4294967295}}}
 --- no_error_log
 [error]
 [crit]
diff --git a/t/04-openresty/ffi/shm/023-metrics_get.t b/t/04-openresty/ffi/shm/023-metrics_get.t
index 8fb31e493..125f58c1b 100644
--- a/t/04-openresty/ffi/shm/023-metrics_get.t
+++ b/t/04-openresty/ffi/shm/023-metrics_get.t
@@ -20,23 +20,29 @@ __DATA__
             local shm = require "resty.wasmx.shm"
             local pretty = require "pl.pretty"
 
+            local bins = { 1, 3, 5 }
+
             local c1 = shm.metrics:define("c1", shm.metrics.COUNTER)
             local g1 = shm.metrics:define("g1", shm.metrics.GAUGE)
             local h1 = shm.metrics:define("h1", shm.metrics.HISTOGRAM)
+            local ch1 = shm.metrics:define("ch1", shm.metrics.HISTOGRAM, { bins = bins })
 
             shm.metrics:increment(c1)
             shm.metrics:record(g1, 10)
             shm.metrics:record(h1, 100)
+            shm.metrics:record(ch1, 2)
 
             ngx.say("c1: ", pretty.write(shm.metrics:get(c1), ""))
             ngx.say("g1: ", pretty.write(shm.metrics:get(g1), ""))
             ngx.say("h1: ", pretty.write(shm.metrics:get(h1), ""))
+            ngx.say("ch1: ", pretty.write(shm.metrics:get(ch1), ""))
         }
     }
 --- response_body
 c1: {type="counter",value=1}
 g1: {type="gauge",value=10}
 h1: {sum=100,type="histogram",value={{count=1,ub=128},{count=0,ub=4294967295}}}
+ch1: {sum=2,type="histogram",value={{count=0,ub=1},{count=1,ub=3},{count=0,ub=5},{count=0,ub=4294967295}}}
 --- no_error_log
 [error]
 [crit]
diff --git a/t/04-openresty/ffi/shm/024-metrics_get_by_name.t b/t/04-openresty/ffi/shm/024-metrics_get_by_name.t
index 95df115b2..09a11e58d 100644
--- a/t/04-openresty/ffi/shm/024-metrics_get_by_name.t
+++ b/t/04-openresty/ffi/shm/024-metrics_get_by_name.t
@@ -21,23 +21,29 @@ prefix: lua.*
             local shm = require "resty.wasmx.shm"
             local pretty = require "pl.pretty"
 
+            local bins = { 1, 3, 5 }
+
             local c1 = shm.metrics:define("c1", shm.metrics.COUNTER)
             local g1 = shm.metrics:define("g1", shm.metrics.GAUGE)
             local h1 = shm.metrics:define("h1", shm.metrics.HISTOGRAM)
+            local ch1 = shm.metrics:define("ch1", shm.metrics.HISTOGRAM, { bins = bins })
 
             shm.metrics:increment(c1)
             shm.metrics:record(g1, 10)
             shm.metrics:record(h1, 100)
+            shm.metrics:record(ch1, 3)
 
             ngx.say("c1: ", pretty.write(shm.metrics:get_by_name("c1"), ""))
             ngx.say("g1: ", pretty.write(shm.metrics:get_by_name("g1"), ""))
             ngx.say("h1: ", pretty.write(shm.metrics:get_by_name("h1"), ""))
+            ngx.say("ch1: ", pretty.write(shm.metrics:get_by_name("ch1"), ""))
         }
     }
 --- response_body
 c1: {type="counter",value=1}
 g1: {type="gauge",value=10}
 h1: {sum=100,type="histogram",value={{count=1,ub=128},{count=0,ub=4294967295}}}
+ch1: {sum=3,type="histogram",value={{count=0,ub=1},{count=1,ub=3},{count=0,ub=5},{count=0,ub=4294967295}}}
 --- no_error_log
 [error]
 [crit]