diff --git a/.github/workflows/rspec.yml b/.github/workflows/rspec.yml
index ce18fa4..ab029fd 100644
--- a/.github/workflows/rspec.yml
+++ b/.github/workflows/rspec.yml
@@ -15,7 +15,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        ruby-version: ['2.7', '3.0', '3.1', '3.2']
+        ruby-version: ['2.7', '3.0', '3.1', '3.2', '3.3']
 
     steps:
     - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
diff --git a/xls_function.gemspec b/xls_function.gemspec
index d505513..650ed9b 100644
--- a/xls_function.gemspec
+++ b/xls_function.gemspec
@@ -26,5 +26,5 @@ Gem::Specification.new do |spec|
 
   spec.add_dependency 'i18n', '>= 1.10.0'
   spec.add_dependency 'parslet', '>= 2.0.0'
-  spec.add_dependency 'wareki', '>= 1.1.0'
+  spec.add_dependency 'wareki', '>= 1.1.0', '< 2'
 end