diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index 54c062b7..1aa47966 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -16,8 +16,8 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        ruby: ['3.2', '3.3', '3.4', '4.0', 'jruby-9.3', 'jruby-9.4', 'jruby-10.0']
-        es_version: ['8.19.14-SNAPSHOT', '9.2.8-SNAPSHOT', '9.3.3-SNAPSHOT', '9.4.0-SNAPSHOT']
+        ruby: ['3.3', '3.4', '4.0', 'jruby-9.3', 'jruby-9.4', 'jruby-10.0']
+        es_version: ['8.19.14-SNAPSHOT', '9.3.3-SNAPSHOT', '9.4.0-SNAPSHOT', '9.5.0-SNAPSHOT']
     runs-on: ubuntu-latest
     steps:
     - uses: actions/checkout@v6
@@ -54,7 +54,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        ruby: ['3.0', '3.1', '3.2', '3.3', 'jruby-9.3']
+        ruby: ['3.3', '3.4', '4.0', 'jruby-9.3', 'jruby-9.4', 'jruby-10.0']
         es_version: ['8.19.14-SNAPSHOT']
     runs-on: ubuntu-latest
     steps:
diff --git a/Gemfile b/Gemfile
index 4c51d07a..898235a8 100644
--- a/Gemfile
+++ b/Gemfile
@@ -36,7 +36,7 @@ group :development, :test do
     gem 'async-http-faraday'
     gem 'curb'
     gem 'faraday-patron'
-    gem 'oj'
+    gem 'oj', '>= 3.17.3', '< 4'
     gem 'debug'
   end
   gem 'rspec'
diff --git a/Gemfile-faraday1.gemfile b/Gemfile-faraday1.gemfile
index 2e075980..889b5b9b 100644
--- a/Gemfile-faraday1.gemfile
+++ b/Gemfile-faraday1.gemfile
@@ -33,10 +33,11 @@ group :development, :test do
   if defined?(JRUBY_VERSION)
     gem 'manticore', platform: :jruby
     gem 'pry-nav'
+    gem 'base64'
   else
     gem 'curb'
     gem 'debug'
-    gem 'oj'
+    gem 'oj', '>= 3.17.3', '< 4'
     gem 'patron'
   end
 end
diff --git a/lib/elastic/transport/client.rb b/lib/elastic/transport/client.rb
index cd0dccc7..a3e83a4a 100644
--- a/lib/elastic/transport/client.rb
+++ b/lib/elastic/transport/client.rb
@@ -169,7 +169,7 @@ def initialize(arguments = {}, &block)
       def perform_request(method, path, params = {}, body = nil, headers = nil, opts = {})
         method = @send_get_body_as if method == 'GET' && body
         validate_ca_fingerprints if @ca_fingerprint
-        if @otel
+        if defined?(@otel) && !@otel.nil?
           # If no endpoint is specified in the opts, use the HTTP method name
           span_name = opts[:endpoint] || method
           @otel.tracer.in_span(span_name) do |span|
diff --git a/lib/elastic/transport/transport/base.rb b/lib/elastic/transport/transport/base.rb
index 19f8eeac..fb3b1af3 100644
--- a/lib/elastic/transport/transport/base.rb
+++ b/lib/elastic/transport/transport/base.rb
@@ -356,15 +356,10 @@ def perform_request(method, path, params = {}, body = nil, headers = nil, opts =
           end
 
           if response.body &&
-            !response.body.empty? &&
-            response.headers &&
-            response.headers["content-type"] =~ /json/
-
-            # Prevent Float value from automatically becoming BigDecimal when using Oj
-            load_options = {}
-            load_options[:mode] = :compat if ::MultiJson.adapter.to_s == "MultiJson::Adapters::Oj"
-
-            json = serializer.load(response.body, load_options)
+             !response.body.empty? &&
+             response.headers &&
+             response.headers['content-type'] =~ /json/
+            json = serializer.load(response.body)
           end
           took = (json['took'] ? sprintf('%.3fs', json['took'] / 1000.0) : 'n/a') rescue 'n/a'
           __log_response(method, path, params, body, url, response, json, took, duration) unless ignore.include?(response.status.to_i)