diff --git a/Calculator-LTI/Gemfile.lock b/Calculator-LTI/Gemfile.lock
index 48cf2e7..fe2e7d6 100644
--- a/Calculator-LTI/Gemfile.lock
+++ b/Calculator-LTI/Gemfile.lock
@@ -100,7 +100,7 @@ GEM
     public_suffix (3.0.0)
     puma (4.3.1)
       nio4r (~> 2.0)
-    rack (2.0.8)
+    rack (2.2.3)
     rack-test (0.7.0)
       rack (>= 1.0, < 3)
     rails (5.1.4)