diff --git a/src/filesystem/implementation.js b/src/filesystem/implementation.js
index aab3a1f..d3e6e9a 100644
--- a/src/filesystem/implementation.js
+++ b/src/filesystem/implementation.js
@@ -1550,10 +1550,13 @@ function validate_file_options(options, enc, fileMode){
 
 function pathCheck(path, callback) {
   var err;
-  if(isNullPath(path)) {
+
+  if(!path) {
+    err = new Errors.EINVAL('Path must be a string', path);
+  } else if(isNullPath(path)) {
     err = new Errors.EINVAL('Path must be a string without null bytes.', path);
   } else if(!isAbsolutePath(path)) {
-    err = new Errors.EINAVL('Path must be absolute.', path);
+    err = new Errors.EINVAL('Path must be absolute.', path);
   }
 
   if(err) {
diff --git a/tests/bugs/issue270.js b/tests/bugs/issue270.js
new file mode 100644
index 0000000..21b4a23
--- /dev/null
+++ b/tests/bugs/issue270.js
@@ -0,0 +1,28 @@
+var Filer = require('../..');
+var util = require('../lib/test-utils.js');
+var expect = require('chai').expect;
+
+describe('undefined and relative paths, issue270', function() {
+  beforeEach(util.setup);
+  afterEach(util.cleanup);
+
+  it('should fail with EINVAL when called on an undefined path', function(done) {
+    var fs = util.fs();
+
+    fs.writeFile(undefined, 'data', function(err) {
+      expect(err).to.exist;
+      expect(err.code).to.equal('EINVAL');
+      done();
+    });
+  });
+
+  it('should fail with EINVAL when called on a relative path', function(done) {
+    var fs = util.fs();
+
+    fs.writeFile('relpath/file.txt', 'data', function(err) {
+      expect(err).to.exist;
+      expect(err.code).to.equal('EINVAL');
+      done();
+    });
+  });
+});
diff --git a/tests/index.js b/tests/index.js
index 601a4a4..9155550 100644
--- a/tests/index.js
+++ b/tests/index.js
@@ -75,3 +75,4 @@ require("./bugs/issue247.js");
 require("./bugs/issue254.js");
 require("./bugs/issue258.js");
 require("./bugs/issue267.js");
+require("./bugs/issue270.js");