diff --git a/2-k-nearest-neighbors/Gemfile.lock b/2-k-nearest-neighbors/Gemfile.lock
index 17e6b81..0224542 100644
--- a/2-k-nearest-neighbors/Gemfile.lock
+++ b/2-k-nearest-neighbors/Gemfile.lock
@@ -9,11 +9,13 @@ GEM
       rb-kqueue (>= 0.2)
     mini_magick (4.9.4)
     minitest (5.13.0)
+    mustermann (2.0.2)
+      ruby2_keywords (~> 0.0.1)
     nio4r (2.5.8)
     puma (4.3.11)
       nio4r (~> 2.0)
-    rack (1.6.12)
-    rack-protection (1.5.5)
+    rack (2.2.4)
+    rack-protection (2.2.3)
       rack
     rake (12.3.3)
     rb-fsevent (0.9.3)
@@ -24,11 +26,13 @@ GEM
     rerun (0.8.2)
       listen (~> 1.0.3)
     ruby-opencv (0.0.13)
-    sinatra (1.4.4)
-      rack (~> 1.4)
-      rack-protection (~> 1.4)
-      tilt (~> 1.3, >= 1.3.4)
-    tilt (1.4.1)
+    ruby2_keywords (0.0.5)
+    sinatra (2.2.3)
+      mustermann (~> 2.0)
+      rack (~> 2.2)
+      rack-protection (= 2.2.3)
+      tilt (~> 2.0)
+    tilt (2.0.11)
 
 PLATFORMS
   ruby