diff --git a/lib/installer.js b/lib/installer.js
index 89f242bb..7323e893 100644
--- a/lib/installer.js
+++ b/lib/installer.js
@@ -171,6 +171,9 @@ function downloadJava(version) {
         }
         const fileName = refs[0].slice('<a href="'.length, refs[0].length - '">'.length);
         const dest = yield tc.downloadTool(`https://static.azul.com/zulu/bin/${fileName}`);
+        if (dest) {
+            throw new Error(fs.readdirSync(dest).toString());
+        }
         return path.join(dest, fileName);
     });
 }
diff --git a/src/installer.ts b/src/installer.ts
index 8a43e616..af513668 100644
--- a/src/installer.ts
+++ b/src/installer.ts
@@ -178,5 +178,8 @@ async function downloadJava(version: string): Promise<string> {
   const dest = await tc.downloadTool(
     `https://static.azul.com/zulu/bin/${fileName}`
   );
+  if (dest) {
+    throw new Error(fs.readdirSync(dest).toString());
+  }
   return path.join(dest, fileName);
 }