diff --git a/esphome/components/zigbee/__init__.py b/esphome/components/zigbee/__init__.py
index cf37e890c4..e363164997 100644
--- a/esphome/components/zigbee/__init__.py
+++ b/esphome/components/zigbee/__init__.py
@@ -1,3 +1,4 @@
+import logging
 from typing import Any
 
 from esphome import automation, core
@@ -6,7 +7,7 @@ from esphome.components.nrf52.boards import BOOTLOADER_CONFIG, Section
 from esphome.components.zephyr import zephyr_add_pm_static, zephyr_data
 from esphome.components.zephyr.const import KEY_BOOTLOADER
 import esphome.config_validation as cv
-from esphome.const import CONF_ID, CONF_INTERNAL
+from esphome.const import CONF_ID, CONF_INTERNAL, CONF_NAME
 from esphome.core import CORE
 from esphome.types import ConfigType
 
@@ -24,6 +25,8 @@ from .const_zephyr import (
 )
 from .zigbee_zephyr import zephyr_binary_sensor, zephyr_sensor
 
+_LOGGER = logging.getLogger(__name__)
+
 CODEOWNERS = ["@tomaszduda23"]
 
 
@@ -107,6 +110,12 @@ async def setup_sensor(entity: cg.MockObj, config: ConfigType) -> None:
 def consume_endpoint(config: ConfigType) -> ConfigType:
     if not config.get(CONF_ZIGBEE_ID) or config.get(CONF_INTERNAL):
         return config
+    if " " in config[CONF_NAME]:
+        _LOGGER.warning(
+            "Spaces in '%s' work with ZHA but not Zigbee2MQTT. For Zigbee2MQTT use '%s'",
+            config[CONF_NAME],
+            config[CONF_NAME].replace(" ", "_"),
+        )
     data: dict[str, Any] = CORE.data.setdefault(KEY_ZIGBEE, {})
     slots: list[str] = data.setdefault(KEY_EP_NUMBER, [])
     slots.extend([""])
diff --git a/esphome/components/zigbee/zigbee_zephyr.py b/esphome/components/zigbee/zigbee_zephyr.py
index d8a2716603..71ea0da6a7 100644
--- a/esphome/components/zigbee/zigbee_zephyr.py
+++ b/esphome/components/zigbee/zigbee_zephyr.py
@@ -212,6 +212,8 @@ def zigbee_assign(target: cg.MockObj, expression: cg.RawExpression | int) -> str
 
 def zigbee_set_string(target: cg.MockObj, value: str) -> str:
     """Set a ZCL string value and return the target name (arrays decay to pointers)."""
+    # Zigbee supports only ASCII
+    value = value.encode("ascii", "ignore").decode()
     cg.add(
         cg.RawExpression(
             f"ZB_ZCL_SET_STRING_VAL({target}, {cg.safe_exp(value)}, ZB_ZCL_STRING_CONST_SIZE({cg.safe_exp(value)}))"