diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index d62eabc..ef0cfb5 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -9,6 +9,11 @@ jobs:
       matrix:
         ruby: [ 3.1, '3.0', 2.7, 2.6, 2.5, 2.4, head, truffleruby ]
         os: [ ubuntu-latest, macos-latest ]
+        exclude:
+          - ruby: 2.4
+            os: macos-latest
+          - ruby: 2.5
+            os: macos-latest
     runs-on: ${{ matrix.os }}
     steps:
     - uses: actions/checkout@v3
diff --git a/lib/uri/common.rb b/lib/uri/common.rb
index ca38bec..0c4064a 100644
--- a/lib/uri/common.rb
+++ b/lib/uri/common.rb
@@ -19,6 +19,8 @@ module URI
   Parser = RFC2396_Parser
   RFC3986_PARSER = RFC3986_Parser.new
   Ractor.make_shareable(RFC3986_PARSER) if defined?(Ractor)
+  RFC2396_PARSER = RFC2396_Parser.new
+  Ractor.make_shareable(RFC2396_PARSER) if defined?(Ractor)
 
   # URI::Parser.new
   DEFAULT_PARSER = Parser.new