diff --git a/modules/file/file.field.inc b/modules/file/file.field.inc
index 973031629c..0ce6c17291 100644
--- a/modules/file/file.field.inc
+++ b/modules/file/file.field.inc
@@ -943,7 +943,7 @@ function theme_file_upload_help($variables) {
 
   $descriptions = array();
 
-  if (strlen($description)) {
+  if (!empty($description)) {
     $descriptions[] = $description;
   }
   if (isset($upload_validators['file_validate_size'])) {
diff --git a/modules/file/tests/file.test b/modules/file/tests/file.test
index 3f9c6de88a..bbd385b560 100644
--- a/modules/file/tests/file.test
+++ b/modules/file/tests/file.test
@@ -1933,3 +1933,26 @@ class FileScanDirectory extends FileFieldTestCase {
   }
 
 }
+
+/**
+ * Test theme implementations declared in file_theme().
+ */
+class FileThemeImplementationsTestCase extends DrupalUnitTestCase {
+
+  public static function getInfo() {
+    return array(
+      'name' => 'Theme implementations declared in file_theme()',
+      'description' => 'Unit tests theme functions in the file module.',
+      'group' => 'File',
+    );
+  }
+
+  function testThemeFileUploadHelp() {
+    $variables = array(
+      'description' => NULL,
+      'upload_validators' => NULL,
+    );
+    $this->assertEqual('', theme_file_upload_help($variables), 'Empty string returned by theme_file_upload_help() with NULL inputs.');
+  }
+
+}