diff --git a/Gemfile b/Gemfile
index 6609061..6df6796 100644
--- a/Gemfile
+++ b/Gemfile
@@ -3,7 +3,7 @@ source "https://rubygems.org"
 ruby "~> 2.5.0"
 
 gem "slack-ruby-bot"
-gem "celluloid-io"
+gem "async-websocket", "~>0.8.0"
 gem "puma"
 gem "sinatra"
 gem "dotenv"
diff --git a/Gemfile.lock b/Gemfile.lock
index c4b4c25..cda9693 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -7,29 +7,18 @@ GEM
       minitest (~> 5.1)
       tzinfo (~> 1.1)
       zeitwerk (~> 2.2)
-    celluloid (0.17.4)
-      celluloid-essentials
-      celluloid-extras
-      celluloid-fsm
-      celluloid-pool
-      celluloid-supervision
-      timers (>= 4.1.1)
-    celluloid-essentials (0.20.5)
-      timers (>= 4.1.1)
-    celluloid-extras (0.20.5)
-      timers (>= 4.1.1)
-    celluloid-fsm (0.20.5)
-      timers (>= 4.1.1)
-    celluloid-io (0.17.3)
-      celluloid (>= 0.17.2)
-      nio4r (>= 1.1)
-      timers (>= 4.1.1)
-    celluloid-pool (0.20.5)
-      timers (>= 4.1.1)
-    celluloid-supervision (0.20.6)
-      timers (>= 4.1.1)
+    async (1.26.0)
+      console (~> 1.0)
+      nio4r (~> 2.3)
+      timers (~> 4.1)
+    async-io (1.29.0)
+      async (~> 1.14)
+    async-websocket (0.8.0)
+      async-io
+      websocket-driver (~> 0.7.0)
     coderay (1.1.2)
     concurrent-ruby (1.1.6)
+    console (1.8.2)
     diff-lcs (1.3)
     dotenv (2.7.5)
     faraday (1.0.1)
@@ -112,7 +101,7 @@ PLATFORMS
   ruby
 
 DEPENDENCIES
-  celluloid-io
+  async-websocket (~> 0.8.0)
   dotenv
   foreman
   httparty