diff --git a/dist/idbfs.js b/dist/idbfs.js
index a30495d..c7701c1 100644
--- a/dist/idbfs.js
+++ b/dist/idbfs.js
@@ -8866,6 +8866,10 @@ define('src/fs',['require','lodash','encoding-indexes','encoding','src/path','sr
       callback(new EInvalid('flags is not valid'));
     }
 
+    data = data || '';
+    if(typeof data === "number") {
+      data = '' + data;
+    }
     if(typeof data === "string" && options.encoding === 'utf8') {
       data = new TextEncoder('utf-8').encode(data);
     }
diff --git a/src/fs.js b/src/fs.js
index a3ccd31..76ad549 100644
--- a/src/fs.js
+++ b/src/fs.js
@@ -1317,6 +1317,10 @@ define(function(require) {
       callback(new EInvalid('flags is not valid'));
     }
 
+    data = data || '';
+    if(typeof data === "number") {
+      data = '' + data;
+    }
     if(typeof data === "string" && options.encoding === 'utf8') {
       data = new TextEncoder('utf-8').encode(data);
     }
diff --git a/tests/spec/node.spec.js b/tests/spec/node.spec.js
index c370a0f..fe21914 100644
--- a/tests/spec/node.spec.js
+++ b/tests/spec/node.spec.js
@@ -108,7 +108,9 @@ describe("node.js tests from https://github.com/joyent/node/blob/master/test", f
     check(fs.symlink,     'foo\u0000bar', 'foobar');
     check(fs.symlink,     'foobar', 'foo\u0000bar');
     check(fs.unlink,      'foo\u0000bar');
-    check(fs.writeFile,   'foo\u0000bar');
+    // NOTE: the node.js test doesn't pass anything for the data arg
+    // but this just seems wrong based on their docs. Here I use one.
+    check(fs.writeFile,   'foo\u0000bar', 'foobar');
 // TODO - need to be implemented still...
 //  check(fs.appendFile,  'foo\u0000bar');
 //  check(fs.realpath,    'foo\u0000bar');