diff --git a/src/main.ts b/src/main.ts
index b449dc3..bd74080 100644
--- a/src/main.ts
+++ b/src/main.ts
@@ -128,7 +128,11 @@ async function run(): Promise<void> {
     core.addPath(toolFolderPath)
     core.debug(`Tool path added to PATH: ${toolFolderPath}`)
   } catch (error) {
-    core.setFailed(error.message)
+    if (error instanceof Error) {
+      core.setFailed(error.message)
+    } else {
+      core.setFailed('Unknown error')
+    }
   }
 }