diff --git a/notebooks/dotNETNotebooks/dbachecks/book/Gemfile.lock b/notebooks/dotNETNotebooks/dbachecks/book/Gemfile.lock
index 893479d..2a79f56 100644
--- a/notebooks/dotNETNotebooks/dbachecks/book/Gemfile.lock
+++ b/notebooks/dotNETNotebooks/dbachecks/book/Gemfile.lock
@@ -249,7 +249,7 @@ GEM
     multipart-post (2.1.1)
     namae (1.0.1)
     nenv (0.3.0)
-    nokogiri (1.10.4)
+    nokogiri (1.10.9)
       mini_portile2 (~> 2.4.0)
     notiffany (0.1.3)
       nenv (~> 0.1)