diff --git a/homeassistant/components/mysensors/const.py b/homeassistant/components/mysensors/const.py
index 700c2bb930a..1b8fa5e24e8 100644
--- a/homeassistant/components/mysensors/const.py
+++ b/homeassistant/components/mysensors/const.py
@@ -29,7 +29,6 @@ CONF_GATEWAY_TYPE_ALL: List[str] = [
 
 
 DOMAIN: str = "mysensors"
-MYSENSORS_GATEWAY_READY: str = "mysensors_gateway_ready_{}"
 MYSENSORS_GATEWAY_START_TASK: str = "mysensors_gateway_start_task_{}"
 MYSENSORS_GATEWAYS: str = "mysensors_gateways"
 PLATFORM: str = "platform"
diff --git a/homeassistant/components/mysensors/gateway.py b/homeassistant/components/mysensors/gateway.py
index 4267ba5cbb3..b6797cafb37 100644
--- a/homeassistant/components/mysensors/gateway.py
+++ b/homeassistant/components/mysensors/gateway.py
@@ -26,7 +26,6 @@ from .const import (
     CONF_TOPIC_OUT_PREFIX,
     CONF_VERSION,
     DOMAIN,
-    MYSENSORS_GATEWAY_READY,
     MYSENSORS_GATEWAY_START_TASK,
     MYSENSORS_GATEWAYS,
     GatewayId,
@@ -36,7 +35,7 @@ from .helpers import discover_mysensors_platform, validate_child, validate_node
 
 _LOGGER = logging.getLogger(__name__)
 
-GATEWAY_READY_TIMEOUT = 15.0
+GATEWAY_READY_TIMEOUT = 20.0
 MQTT_COMPONENT = "mqtt"
 
 
@@ -64,24 +63,16 @@ async def try_connect(hass: HomeAssistantType, user_input: Dict[str, str]) -> bo
     if user_input[CONF_DEVICE] == MQTT_COMPONENT:
         return True  # dont validate mqtt. mqtt gateways dont send ready messages :(
     try:
-        gateway_ready = asyncio.Future()
+        gateway_ready = asyncio.Event()
 
-        def gateway_ready_callback(msg):
-            msg_type = msg.gateway.const.MessageType(msg.type)
-            _LOGGER.debug("Received MySensors msg type %s: %s", msg_type.name, msg)
-            if msg_type.name != "internal":
-                return
-            internal = msg.gateway.const.Internal(msg.sub_type)
-            if internal.name != "I_GATEWAY_READY":
-                return
-            _LOGGER.debug("Received gateway ready")
-            gateway_ready.set_result(True)
+        def on_conn_made(_: BaseAsyncGateway) -> None:
+            gateway_ready.set()
 
         gateway: Optional[BaseAsyncGateway] = await _get_gateway(
             hass,
             device=user_input[CONF_DEVICE],
             version=user_input[CONF_VERSION],
-            event_callback=gateway_ready_callback,
+            event_callback=lambda _: None,
             persistence_file=None,
             baud_rate=user_input.get(CONF_BAUD_RATE),
             tcp_port=user_input.get(CONF_TCP_PORT),
@@ -92,12 +83,13 @@ async def try_connect(hass: HomeAssistantType, user_input: Dict[str, str]) -> bo
         )
         if gateway is None:
             return False
+        gateway.on_conn_made = on_conn_made
 
         connect_task = None
         try:
             connect_task = asyncio.create_task(gateway.start())
-            with async_timeout.timeout(20):
-                await gateway_ready
+            with async_timeout.timeout(GATEWAY_READY_TIMEOUT):
+                await gateway_ready.wait()
                 return True
         except asyncio.TimeoutError:
             _LOGGER.info("Try gateway connect failed with timeout")
@@ -280,6 +272,12 @@ async def _gw_start(
     hass: HomeAssistantType, entry: ConfigEntry, gateway: BaseAsyncGateway
 ):
     """Start the gateway."""
+    gateway_ready = asyncio.Event()
+
+    def gateway_connected(_: BaseAsyncGateway):
+        gateway_ready.set()
+
+    gateway.on_conn_made = gateway_connected
     # Don't use hass.async_create_task to avoid holding up setup indefinitely.
     hass.data[DOMAIN][
         MYSENSORS_GATEWAY_START_TASK.format(entry.entry_id)
@@ -294,21 +292,15 @@ async def _gw_start(
     if entry.data[CONF_DEVICE] == MQTT_COMPONENT:
         # Gatways connected via mqtt doesn't send gateway ready message.
         return
-    gateway_ready = asyncio.Future()
-    gateway_ready_key = MYSENSORS_GATEWAY_READY.format(entry.entry_id)
-    hass.data[DOMAIN][gateway_ready_key] = gateway_ready
-
     try:
         with async_timeout.timeout(GATEWAY_READY_TIMEOUT):
-            await gateway_ready
+            await gateway_ready.wait()
     except asyncio.TimeoutError:
         _LOGGER.warning(
-            "Gateway %s not ready after %s secs so continuing with setup",
+            "Gateway %s not connected after %s secs so continuing with setup",
             entry.data[CONF_DEVICE],
             GATEWAY_READY_TIMEOUT,
         )
-    finally:
-        hass.data[DOMAIN].pop(gateway_ready_key, None)
 
 
 def _gw_callback_factory(
diff --git a/homeassistant/components/mysensors/handler.py b/homeassistant/components/mysensors/handler.py
index 10165a171e0..a47c9174b23 100644
--- a/homeassistant/components/mysensors/handler.py
+++ b/homeassistant/components/mysensors/handler.py
@@ -8,14 +8,7 @@ from homeassistant.helpers.dispatcher import async_dispatcher_send
 from homeassistant.helpers.typing import HomeAssistantType
 from homeassistant.util import decorator
 
-from .const import (
-    CHILD_CALLBACK,
-    DOMAIN,
-    MYSENSORS_GATEWAY_READY,
-    NODE_CALLBACK,
-    DevId,
-    GatewayId,
-)
+from .const import CHILD_CALLBACK, NODE_CALLBACK, DevId, GatewayId
 from .device import get_mysensors_devices
 from .helpers import discover_mysensors_platform, validate_set_msg
 
@@ -75,20 +68,6 @@ async def handle_sketch_version(
     _handle_node_update(hass, gateway_id, msg)
 
 
-@HANDLERS.register("I_GATEWAY_READY")
-async def handle_gateway_ready(
-    hass: HomeAssistantType, gateway_id: GatewayId, msg: Message
-) -> None:
-    """Handle an internal gateway ready message.
-
-    Set asyncio future result if gateway is ready.
-    """
-    gateway_ready = hass.data[DOMAIN].get(MYSENSORS_GATEWAY_READY.format(gateway_id))
-    if gateway_ready is None or gateway_ready.cancelled():
-        return
-    gateway_ready.set_result(True)
-
-
 @callback
 def _handle_child_update(
     hass: HomeAssistantType, gateway_id: GatewayId, validated: Dict[str, List[DevId]]