diff --git a/docs/usage/cli.en.md b/docs/usage/cli.en.md
index 0b700725..6d315485 100644
--- a/docs/usage/cli.en.md
+++ b/docs/usage/cli.en.md
@@ -410,8 +410,8 @@ Create a pool. Required parameters:
 
 | <!-- -->                 | <!-- -->                                                                                |
 |--------------------------|-----------------------------------------------------------------------------------------|
-| `-s R` or `--pg_size R`  | Number of replicas for replicated pools                                                 |
-| `--ec N+K`               | Number of data (N) and parity (K) chunks for erasure-coded pools                        |
+| `-s R` or `--pg_size R`  | Number of replicas for replicated pools, from 1 to 64                                   |
+| `--ec N+K`               | Number of data (N) and parity (K) chunks for erasure-coded pools, N+K from 3 to 64      |
 | `-n N` or `--pg_count N` | PG count for the new pool (start with 10*\<OSD count\>/pg_size rounded to a power of 2) |
 
 Optional parameters:
diff --git a/docs/usage/cli.ru.md b/docs/usage/cli.ru.md
index e4787d15..16ec40b7 100644
--- a/docs/usage/cli.ru.md
+++ b/docs/usage/cli.ru.md
@@ -429,8 +429,8 @@ OSD  PARENT            UP    SIZE  USED%    TAGS          WEIGHT  BLOCK  BITMAP
 
 | <!-- -->                  | <!-- -->                                                                                      |
 |---------------------------|-----------------------------------------------------------------------------------------------|
-| `-s R` или `--pg_size R`  | Число копий данных для реплицированных пулов                                                  |
-| `--ec N+K`                | Число частей данных (N) и чётности (K) для пулов с кодами коррекции ошибок                    |
+| `-s R` или `--pg_size R`  | Число копий данных для реплицированных пулов, от 1 до 64                                      |
+| `--ec N+K`                | Число частей данных (N) и чётности (K) для пулов с кодами коррекции ошибок, N+K от 3 до 64    |
 | `-n N` или `--pg_count N` | Число PG для нового пула (начните с 10*\<число OSD\>/pg_size, округлённого до степени двойки) |
 
 Необязательные параметры:
diff --git a/src/cmd/cli.cpp b/src/cmd/cli.cpp
index 28ba05af..57354401 100644
--- a/src/cmd/cli.cpp
+++ b/src/cmd/cli.cpp
@@ -197,8 +197,8 @@ static const char* help_text =
     "\n"
     "vitastor-cli create-pool|pool-create <name> (-s <pg_size>|--ec <N>+<K>) -n <pg_count> [OPTIONS]\n"
     "  Create a pool. Required parameters:\n"
-    "    -s|--pg_size R   Number of replicas for replicated pools\n"
-    "    --ec N+K         Number of data (N) and parity (K) chunks for erasure-coded pools\n"
+    "    -s|--pg_size R   Number of replicas for replicated pools, from 1 to 64\n"
+    "    --ec N+K         Number of data (N) and parity (K) chunks for erasure-coded pools, N+K from 3 to 64\n"
     "    -n|--pg_count N  PG count for the new pool (start with 10*<OSD count>/pg_size rounded to a power of 2)\n"
     "  Optional parameters:\n"
     "    --pg_minsize <number>         R or N+K minus number of failures to tolerate without downtime\n"
diff --git a/src/cmd/cli_pool_cfg.cpp b/src/cmd/cli_pool_cfg.cpp
index 83cb2ff6..459a16fe 100644
--- a/src/cmd/cli_pool_cfg.cpp
+++ b/src/cmd/cli_pool_cfg.cpp
@@ -233,9 +233,10 @@ std::string validate_pool_config(json11::Json::object & new_cfg, json11::Json ol
     {
         return "PG size can't be smaller than 3 for EC/XOR pools";
     }
-    if (pg_size > 256)
+    // same limit as in etcd_state_client.cpp and mon/pool_config.js
+    if (pg_size > 64)
     {
-        return "PG size can't be greater than 256";
+        return "PG size can't be greater than 64";
     }
 
     // PG rules
diff --git a/tests/run_tests.sh b/tests/run_tests.sh
index d72fcf78..5a4323c0 100755
--- a/tests/run_tests.sh
+++ b/tests/run_tests.sh
@@ -48,6 +48,8 @@ OLD=1 SCHEME=ec IMMEDIATE_COMMIT=1 ./test_interrupted_rebalance.sh
 
 ./test_failure_domain.sh
 
+./test_pool_pg_size_limit.sh
+
 ./test_level_placement.sh
 
 ./test_snapshot.sh
diff --git a/tests/test_pool_pg_size_limit.sh b/tests/test_pool_pg_size_limit.sh
new file mode 100755
index 00000000..c92f9c4f
--- /dev/null
+++ b/tests/test_pool_pg_size_limit.sh
@@ -0,0 +1,27 @@
+#!/bin/bash -ex
+
+# Test that create-pool and modify-pool refuse pg_size > 64, which OSDs and clients don't support
+
+. `dirname $0`/common.sh
+
+wait_etcd
+
+$ETCDCTL put /vitastor/config/pools '{"1":{"name":"testpool","scheme":"replicated","pg_size":2,"pg_minsize":1,"pg_count":1,"failure_domain":"osd"}}'
+
+for args in "create-pool bigpool -s 65 -n 1 --force" "create-pool bigpool --ec 62+3 -n 1 --force" "modify-pool testpool -s 65"; do
+    r=0
+    $VITASTOR_CLI $args || r=$?
+    if [[ $r != 22 ]]; then
+        format_error "$args should fail with EINVAL (22), but exited with $r"
+    fi
+done
+
+$ETCDCTL get --print-value-only /vitastor/config/pools | jq -e 'keys == ["1"] and .["1"].pg_size == 2' || \
+    format_error "Pool configuration should not change after refused commands"
+
+# 64 is still accepted
+$VITASTOR_CLI modify-pool testpool -s 64
+$ETCDCTL get --print-value-only /vitastor/config/pools | jq -e '.["1"].pg_size == 64' || \
+    format_error "modify-pool -s 64 should set pg_size to 64"
+
+format_green OK