diff --git a/docs/ledger.md b/docs/ledger.md
index fcaa85d..5a59107 100644
--- a/docs/ledger.md
+++ b/docs/ledger.md
@@ -1,6 +1,7 @@
 # Ledger Nano S
 
 The Ledger Nano S is supported by HWI.
+Note that the Bitcoin App must be installed and running on the device.
 
 Currently implemented commands: