diff --git a/lib/storage/file.js b/lib/storage/file.js
index df6e60d57b7..e3bc507e986 100644
--- a/lib/storage/file.js
+++ b/lib/storage/file.js
@@ -114,11 +114,12 @@ function File(bucket, name, options) {
     value: name
   });
 
+  var generation = parseInt(options.generation, 10);
   var requestQueryObject = {};
 
-  if (is.number(options.generation)) {
-    requestQueryObject.generation = options.generation;
-    this.generation = options.generation;
+  if (!isNaN(generation)) {
+    requestQueryObject.generation = generation;
+    this.generation = generation;
   }
 
   var methods = {
@@ -372,7 +373,7 @@ File.prototype.copy = function(destination, callback) {
   }
 
   var query = {};
-  if (is.number(this.generation)) {
+  if (is.defined(this.generation)) {
     query.sourceGeneration = this.generation;
   }
 
@@ -1464,7 +1465,7 @@ File.prototype.startSimpleUpload_ = function(dup, metadata) {
     })
   };
 
-  if (is.number(this.generation)) {
+  if (is.defined(this.generation)) {
     reqOpts.qs.ifGenerationMatch = this.generation;
   }