diff --git a/homeassistant/components/tplink/strings.json b/homeassistant/components/tplink/strings.json
index 664d52c16af7edb3cf31f0c465ef491895a39064..c0aef09e8c324372304132d41648599d01bc5222 100644
--- a/homeassistant/components/tplink/strings.json
+++ b/homeassistant/components/tplink/strings.json
@@ -21,7 +21,7 @@
       },
       "user_auth_confirm": {
         "title": "Authenticate",
-        "description": "The device requires authentication, please input your TP-Link credentials below.",
+        "description": "The device requires authentication, please input your TP-Link credentials below. Note, that both e-mail and password are case-sensitive.",
         "data": {
           "username": "[%key:common::config_flow::data::username%]",
           "password": "[%key:common::config_flow::data::password%]"