diff --git a/modules/user/user.module b/modules/user/user.module
index 874efae6d6e16dece1d748cd4550c7cc19b84ed5..45ea7f280362e090a09b0ea18c1b063499bc2001 100644
--- a/modules/user/user.module
+++ b/modules/user/user.module
@@ -1409,7 +1409,9 @@ function template_preprocess_user_picture(&$variables) {
     }
     if (isset($filepath)) {
       $alt = t("@user's picture", array('@user' => format_username($account)));
-      if (module_exists('image') && $style = variable_get('user_picture_style', '')) {
+      // If the image does not have a valid Drupal scheme (for eg. HTTP),
+      // don't load image styles.
+      if (module_exists('image') && file_valid_uri($filepath) && $style = variable_get('user_picture_style', '')) {
         $variables['user_picture'] = theme('image_style', array('style_name' => $style, 'path' => $filepath, 'alt' => $alt, 'title' => $alt));
       }
       else {
diff --git a/modules/user/user.test b/modules/user/user.test
index 91549f0de3b00574f18c184b06486aa7527b8224..2cfb45671d5658891450c95f043e5359309173f2 100644
--- a/modules/user/user.test
+++ b/modules/user/user.test
@@ -916,6 +916,26 @@ class UserPictureTestCase extends DrupalWebTestCase {
     }
   }
 
+  /**
+   * Test HTTP schema working with user pictures.
+   */
+  function testExternalPicture() {
+    $this->drupalLogin($this->user);
+    // Set the default picture to an URI with a HTTP schema.
+    $images = $this->drupalGetTestFiles('image');
+    $image = $images[0];
+    $pic_path = file_create_url($image->uri);
+    variable_set('user_picture_default', $pic_path);
+
+    // Check if image is displayed in user's profile page.
+    $this->drupalGet('user');
+
+    // Get the user picture image via xpath.
+    $elements = $this->xpath('//div[@class="user-picture"]/img');
+    $this->assertEqual(count($elements), 1, t("There is exactly one user picture on the user's profile page"));
+    $this->assertEqual($pic_path, (string) $elements[0]['src'], t("User picture source is correct."));
+  }
+
   function saveUserPicture($image) {
     $edit = array('files[picture_upload]' => drupal_realpath($image->uri));
     $this->drupalPost('user/' . $this->user->uid . '/edit', $edit, t('Save'));