diff --git a/.github/workflows/rspec.yml b/.github/workflows/rspec.yml
index 0bf4112..325c5d1 100755
--- a/.github/workflows/rspec.yml
+++ b/.github/workflows/rspec.yml
@@ -12,7 +12,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        ruby-version: ['3.1', '3.0', '2.7']
+        ruby-version: ['3.1', '3.0', '2.7', '2.6', '2.5']
     steps:
       - uses: actions/checkout@v2
       - name: Set up Ruby ${{ matrix.ruby-version }}
diff --git a/lib/sniffer/adapters/ethon_adapter.rb b/lib/sniffer/adapters/ethon_adapter.rb
index 2a93d88..7c1bef5 100644
--- a/lib/sniffer/adapters/ethon_adapter.rb
+++ b/lib/sniffer/adapters/ethon_adapter.rb
@@ -93,16 +93,14 @@ def perform
 
 if defined?(::Ethon::Easy)
   if defined?(Sniffer::Adapters::EthonAdapter::PREPEND)
-    Ethon::Easy::Http.prepend Sniffer::Adapters::EthonAdapter::Http::Prepend
-    Ethon::Easy::Operations.prepend Sniffer::Adapters::EthonAdapter::Operations::Prepend
+    Ethon::Easy.prepend Sniffer::Adapters::EthonAdapter::Http::Prepend
+    Ethon::Easy.prepend Sniffer::Adapters::EthonAdapter::Operations::Prepend
   else
-    Ethon::Easy::Http.class_eval do
+    Ethon::Easy.class_eval do
       include Sniffer::Adapters::EthonAdapter::Http
       alias_method :http_request_without_sniffer, :http_request
       alias_method :http_request, :http_request_with_sniffer
-    end
 
-    Ethon::Easy::Operations.class_eval do
       include Sniffer::Adapters::EthonAdapter::Operations
       alias_method :perform_without_sniffer, :perform
       alias_method :perform, :perform_with_sniffer