diff --git a/tools/check_web_sanity.js b/tools/check_web_sanity.js
index 79cf959..77838dd 100755
--- a/tools/check_web_sanity.js
+++ b/tools/check_web_sanity.js
@@ -16,7 +16,7 @@
 var fs = require('fs');
 var process = require('process');
 
-var source = fs.readFileSync(process.stdin.fd).toString();
+var source = fs.readFileSync('/dev/stdin').toString();
 
 if (source.match(/Invalid/)) {
   console.log('BAD ASM.JS');