diff --git a/lib/outputlib.php b/lib/outputlib.php
index 77ee70ea0e0..5fe61d348db 100644
--- a/lib/outputlib.php
+++ b/lib/outputlib.php
@@ -1646,12 +1646,13 @@ class theme_config {
      *
      * Use this function sparingly and never for icons. For icons use pix_icon or the pix helper in a mustache template.
      *
+     * @deprecated since Moodle 3.3
      * @param string $imagename the name of the icon.
      * @param string $component specification of one plugin like in get_string()
      * @return moodle_url
      */
     public function pix_url($imagename, $component) {
-        debugging('pix_url is deprecated. Use image_url for images and pix_icon for icons.');
+        debugging('pix_url is deprecated. Use image_url for images and pix_icon for icons.', DEBUG_DEVELOPER);
         return $this->image_url($imagename, $component);
     }
 
diff --git a/lib/outputrenderers.php b/lib/outputrenderers.php
index c57bb73bec3..7406646d05b 100644
--- a/lib/outputrenderers.php
+++ b/lib/outputrenderers.php
@@ -253,8 +253,18 @@ class renderer_base {
         return $classes;
     }
 
+    /**
+     * Return the direct URL for an image from the pix folder.
+     *
+     * Use this function sparingly and never for icons. For icons use pix_icon or the pix helper in a mustache template.
+     *
+     * @deprecated since Moodle 3.3
+     * @param string $imagename the name of the icon.
+     * @param string $component specification of one plugin like in get_string()
+     * @return moodle_url
+     */
     public function pix_url($imagename, $component = 'moodle') {
-        debugging('pix_url is deprecated. Use image_url for images and pix_icon for icons.');
+        debugging('pix_url is deprecated. Use image_url for images and pix_icon for icons.', DEBUG_DEVELOPER);
         return $this->page->theme->image_url($imagename, $component);
     }
 
diff --git a/repository/onedrive/lib.php b/repository/onedrive/lib.php
index 73118a34230..3e802124193 100644
--- a/repository/onedrive/lib.php
+++ b/repository/onedrive/lib.php
@@ -283,6 +283,8 @@ class repository_onedrive extends repository {
      * @param string $parent Parent id.
      * @param int $page page.
      * @return array of files and folders.
+     * @throws Exception
+     * @throws repository_exception
      */
     protected function query($q, $path = null, $parent = null, $page = 0) {
         global $OUTPUT;
@@ -322,7 +324,7 @@ class repository_onedrive extends repository {
                     'title' => $remotefile->name,
                     'path' => $this->build_node_path($remotefile->id, $remotefile->name, $path),
                     'date' => strtotime($remotefile->lastModifiedDateTime),
-                    'thumbnail' => $OUTPUT->pix_url(file_folder_icon(64))->out(false),
+                    'thumbnail' => $OUTPUT->image_url(file_folder_icon(64))->out(false),
                     'thumbnail_height' => 64,
                     'thumbnail_width' => 64,
                     'children' => []