diff --git a/.github/lychee.toml b/.github/lychee.toml
index 25beba157..7e23b2351 100644
--- a/.github/lychee.toml
+++ b/.github/lychee.toml
@@ -52,7 +52,8 @@ exclude = [
 # Timeout
 "https://huehive.co",
 "https://foswiki.org",
-"https://www.gnu.org"
+"https://www.gnu.org",
+"https://mermaid-preview.com"
 ]
 
 # Exclude all private IPs from checking.