diff --git a/dist/index.js b/dist/index.js
index 2cc1a62..d8e2eaa 100644
--- a/dist/index.js
+++ b/dist/index.js
@@ -65924,6 +65924,8 @@ function validateRubyEngineAndVersion(platform, engineVersions, engine, parsedVe
           - { os: macos-13, ruby: '2.5' }
 
         But of course you should consider dropping support for these long-EOL Rubies, which cannot even be built on recent macOS machines.`)
+  } else if (engine === 'truffleruby' && platform.startsWith('windows')) {
+    throw new Error('TruffleRuby does not currently support Windows.')
   }
 
   return version
diff --git a/index.js b/index.js
index 85d20f6..599109d 100644
--- a/index.js
+++ b/index.js
@@ -190,6 +190,8 @@ function validateRubyEngineAndVersion(platform, engineVersions, engine, parsedVe
           - { os: macos-13, ruby: '2.5' }
 
         But of course you should consider dropping support for these long-EOL Rubies, which cannot even be built on recent macOS machines.`)
+  } else if (engine === 'truffleruby' && platform.startsWith('windows')) {
+    throw new Error('TruffleRuby does not currently support Windows.')
   }
 
   return version