diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 56110ec..e16f0c3 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -10,7 +10,7 @@ on:
       - main
 
 env:
-  ruby_version: 3.3
+  ruby_version: 3.4
 
 jobs:
   test:
@@ -18,7 +18,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        ruby: [2.7, '3.0', 3.1, 3.2, 3.3, jruby-9.4]
+        ruby: [2.7, '3.0', 3.1, 3.2, 3.3, 3.4, jruby-9.4, jruby-10.0]
     services:
       dynamodb:
         image: amazon/dynamodb-local:latest
diff --git a/lib/aws/session_store/dynamo_db/locking/pessimistic.rb b/lib/aws/session_store/dynamo_db/locking/pessimistic.rb
index 7f5c3d7..36d15bf 100644
--- a/lib/aws/session_store/dynamo_db/locking/pessimistic.rb
+++ b/lib/aws/session_store/dynamo_db/locking/pessimistic.rb
@@ -59,7 +59,7 @@ def get_lock_time_opts(sid)
     # @return [Time] Time stamp for which the session was locked.
     def lock_time(sid)
       result = @config.dynamo_db_client.get_item(get_lock_time_opts(sid))
-      (result[:item]['locked_at']).to_f if result[:item]['locked_at']
+      result[:item]['locked_at']&.to_f
     end
 
     # @return [String] Session data.
@@ -138,7 +138,7 @@ def expect_lock_time(env)
       {
         expected: {
           'locked_at' => {
-            value: (env['locked_at']).to_s,
+            value: env['locked_at'].to_s,
             exists: true
           }
         }
diff --git a/spec/aws/session_store/dynamo_db/rack_middleware_integration_spec.rb b/spec/aws/session_store/dynamo_db/rack_middleware_integration_spec.rb
index 6fbbced..a6ee843 100644
--- a/spec/aws/session_store/dynamo_db/rack_middleware_integration_spec.rb
+++ b/spec/aws/session_store/dynamo_db/rack_middleware_integration_spec.rb
@@ -24,7 +24,7 @@ def attr_opts
 
         def extract_time(sid)
           options = table_opts(sid).merge(attr_opts)
-          Time.at((config.dynamo_db_client.get_item(options)[:item]['created_at']).to_f)
+          Time.at(config.dynamo_db_client.get_item(options)[:item]['created_at'].to_f)
         end
 
         let(:options) do