diff --git a/Gemfile b/Gemfile
index 111bc4e..2b6d51c 100644
--- a/Gemfile
+++ b/Gemfile
@@ -6,7 +6,7 @@ gem "i18n"
 gem "rexml"
 gem "digest-crc"
 gem "ffi"
-gem "async"
+gem "async", "~>1.30.1"
 gem "async-http"
 gem "async-websocket"
 gem "thread-local"
diff --git a/Gemfile.lock b/Gemfile.lock
index 6e747e6..6803f31 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -65,7 +65,7 @@ PLATFORMS
   x86_64-linux
 
 DEPENDENCIES
-  async
+  async (~> 1.30.1)
   async-http
   async-websocket
   cyberarm_engine
@@ -77,4 +77,4 @@ DEPENDENCIES
   thread-local
 
 BUNDLED WITH
-   2.2.28
+   2.3.3