diff --git a/homeassistant/components/knx/__init__.py b/homeassistant/components/knx/__init__.py
index 204f8613883..566b3259288 100644
--- a/homeassistant/components/knx/__init__.py
+++ b/homeassistant/components/knx/__init__.py
@@ -135,9 +135,7 @@ CONFIG_SCHEMA = vol.Schema(
 SERVICE_KNX_SEND_SCHEMA = vol.Schema(
     {
         vol.Required(SERVICE_KNX_ATTR_ADDRESS): cv.string,
-        vol.Required(SERVICE_KNX_ATTR_PAYLOAD): vol.Any(
-            cv.positive_int, [cv.positive_int]
-        ),
+        vol.Required(SERVICE_KNX_ATTR_PAYLOAD): cv.match_all,
         vol.Optional(SERVICE_KNX_ATTR_TYPE): vol.Any(int, float, str),
     }
 )