diff --git a/Gemfile.lock b/Gemfile.lock
index c99e8223b..ef489a414 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -31,8 +31,7 @@ GEM
       mini_portile (~> 0.6.0)
     pdfkit (0.6.2)
     posix-spawn (0.3.11)
-    puma (2.11.2)
-      rack (>= 1.1, < 2.0)
+    puma (3.12.2)
     rack (1.4.5)
     rack-jekyll (0.3.5)
       jekyll