diff --git a/docs/guide.md b/docs/guide.md
index 1fd6910..0408080 100644
--- a/docs/guide.md
+++ b/docs/guide.md
@@ -491,6 +491,7 @@ First, obtain the gpg keys:
 ```sh
 gpg --batch --keyserver keys.openpgp.org     --recv-keys 7D1E8AFD1D4A16D71FADA2F2CCC85C0E40C06A8C
 gpg --batch --keyserver keyserver.ubuntu.com --recv-keys FE5AB6C91FEA597C3B31180B73EDE9E8CFBAEF01
+gpg --batch --keyserver keyserver.ubuntu.com --recv-keys 88B57FCF7DB53B4DB3BFA4B1588764FBE22D19C4
 ```
 
 Then verify the gpg key in one of these ways: