diff --git a/appengine/flexible/ruby31-and-earlier/static_files/sinatra/Gemfile.lock b/appengine/flexible/ruby31-and-earlier/static_files/sinatra/Gemfile.lock
index 56323fda2..9e852cde9 100644
--- a/appengine/flexible/ruby31-and-earlier/static_files/sinatra/Gemfile.lock
+++ b/appengine/flexible/ruby31-and-earlier/static_files/sinatra/Gemfile.lock
@@ -15,6 +15,7 @@ GEM
     mini_mime (1.0.0)
     mini_portile2 (2.4.0)
     mustermann (1.0.2)
+    nio4r (2.5.9)
     nokogiri (1.10.1)
       mini_portile2 (~> 2.4.0)
     poltergeist (1.18.1)
@@ -22,7 +23,8 @@ GEM
       cliver (~> 0.3.1)
       websocket-driver (>= 0.2.0)
     public_suffix (3.0.2)
-    puma (3.12.0)
+    puma (5.6.7)
+      nio4r (~> 2.0)
     rack (2.0.6)
     rack-protection (2.0.3)
       rack
@@ -41,6 +43,8 @@ GEM
       diff-lcs (>= 1.2.0, < 2.0)
       rspec-support (~> 3.7.0)
     rspec-support (3.7.1)
+    rspec_junit_formatter (0.6.0)
+      rspec-core (>= 2, < 4, != 2.12.0)
     sinatra (2.0.3)
       mustermann (~> 1.0)
       rack (~> 2.0)
@@ -65,6 +69,7 @@ DEPENDENCIES
   poltergeist
   puma
   rspec
+  rspec_junit_formatter
   sinatra
   slim