diff --git a/lib/execjs/support/jscript_runner.js b/lib/execjs/support/jscript_runner.js
index 58d53c6..5419625 100644
--- a/lib/execjs/support/jscript_runner.js
+++ b/lib/execjs/support/jscript_runner.js
@@ -16,6 +16,6 @@
       }
     }
   } catch (err) {
-    print(JSON.stringify(['err', '' + err]));
+    print(JSON.stringify(['err', err.name + ': ' + err.message]));
   }
 });