diff --git a/lib/roda/plugins/exception_page.rb b/lib/roda/plugins/exception_page.rb
index c9abd524..e48db6d8 100644
--- a/lib/roda/plugins/exception_page.rb
+++ b/lib/roda/plugins/exception_page.rb
@@ -411,7 +411,7 @@ def exception_page_js
 
         private
 
-        if RUBY_VERSION >= '3.2'
+        if Exception.method_defined?(:detailed_message)
           def exception_page_exception_message(exception)
             exception.detailed_message(highlight: false).to_s
           end
diff --git a/spec/plugin/exception_page_spec.rb b/spec/plugin/exception_page_spec.rb
index 7fd4dc3a..b26a573e 100644
--- a/spec/plugin/exception_page_spec.rb
+++ b/spec/plugin/exception_page_spec.rb
@@ -15,7 +15,7 @@ def req(path = '/', headers={})
     end
   end
 
-  message = RUBY_VERSION >= '3.2' ? "foo (RuntimeError)" : "foo"
+  message = Exception.method_defined?(:detailed_message) ? "foo (RuntimeError)" : "foo"
 
   it "returns HTML page with exception information if text/html is accepted" do
     ep_app