diff -rNaud Thunar-1.8.1/thunar/thunar-icon-factory.c Thunar-1.8.1-NEW/thunar/thunar-icon-factory.c
--- Thunar-1.8.1/thunar/thunar-icon-factory.c	2018-06-12 03:47:24.000000000 +0200
+++ Thunar-1.8.1-NEW/thunar/thunar-icon-factory.c	2018-08-21 17:48:14.822127564 +0200
@@ -847,67 +847,69 @@
     }
 
   /* check if thumbnails are enabled and we can display a thumbnail for the item */
-  if (thunar_icon_factory_get_show_thumbnail (factory, file)
-      && thunar_file_is_regular (file))
+  if (thunar_icon_factory_get_show_thumbnail (factory, file))
     {
-      /* determine the preview icon first */
-      gicon = thunar_file_get_preview_icon (file);
-
-      /* check if we have a preview icon */
-      if (gicon != NULL)
+      if (thunar_file_is_regular (file) || thunar_file_is_directory (file))
         {
-          if (G_IS_THEMED_ICON (gicon))
+          /* determine the preview icon first */
+          gicon = thunar_file_get_preview_icon (file);
+
+          /* check if we have a preview icon */
+          if (gicon != NULL)
             {
-              /* we have a themed preview icon, look it up using the icon theme */
-              icon_info =
-                gtk_icon_theme_lookup_by_gicon (factory->icon_theme,
-                                                gicon, icon_size,
-                                                GTK_ICON_LOOKUP_USE_BUILTIN
-                                                | GTK_ICON_LOOKUP_FORCE_SIZE);
+              if (G_IS_THEMED_ICON (gicon))
+                {
+                  /* we have a themed preview icon, look it up using the icon theme */
+                  icon_info =
+                    gtk_icon_theme_lookup_by_gicon (factory->icon_theme,
+                                                    gicon, icon_size,
+                                                    GTK_ICON_LOOKUP_USE_BUILTIN
+                                                    | GTK_ICON_LOOKUP_FORCE_SIZE);
 
-              /* check if the lookup succeeded */
-              if (icon_info != NULL)
+                  /* check if the lookup succeeded */
+                  if (icon_info != NULL)
+                    {
+                      /* try to load the pixbuf from the icon info */
+                      icon = gtk_icon_info_load_icon (icon_info, NULL);
+                      g_object_unref (icon_info);
+                    }
+                }
+              else if (G_IS_LOADABLE_ICON (gicon))
                 {
-                  /* try to load the pixbuf from the icon info */
-                  icon = gtk_icon_info_load_icon (icon_info, NULL);
-                  g_object_unref (icon_info);
+                  /* we have a loadable icon, try to open it for reading */
+                  stream = g_loadable_icon_load (G_LOADABLE_ICON (gicon), icon_size,
+                                                 NULL, NULL, NULL);
+
+                  /* check if we have a valid input stream */
+                  if (stream != NULL)
+                    {
+                      /* load the pixbuf from the stream */
+                      icon = gdk_pixbuf_new_from_stream_at_scale (stream, icon_size,
+                                                                  icon_size, TRUE,
+                                                                  NULL, NULL);
+
+                      /* destroy the stream */
+                      g_object_unref (stream);
+                    }
                 }
+
+              /* return the icon if we have one */
+              if (icon != NULL)
+                return icon;
             }
-          else if (G_IS_LOADABLE_ICON (gicon))
+          else
             {
-              /* we have a loadable icon, try to open it for reading */
-              stream = g_loadable_icon_load (G_LOADABLE_ICON (gicon), icon_size,
-                                             NULL, NULL, NULL);
+              /* we have no preview icon but the thumbnail should be ready. determine
+               * the filename of the thumbnail */
+              thumbnail_path = thunar_file_get_thumbnail_path (file);
 
-              /* check if we have a valid input stream */
-              if (stream != NULL)
+              /* check if we have a valid path */
+              if (thumbnail_path != NULL)
                 {
-                  /* load the pixbuf from the stream */
-                  icon = gdk_pixbuf_new_from_stream_at_scale (stream, icon_size,
-                                                              icon_size, TRUE,
-                                                              NULL, NULL);
-
-                  /* destroy the stream */
-                  g_object_unref (stream);
+                  /* try to load the thumbnail */
+                  icon = thunar_icon_factory_load_from_file (factory, thumbnail_path, icon_size);
                 }
             }
-
-          /* return the icon if we have one */
-          if (icon != NULL)
-            return icon;
-        }
-      else
-        {
-          /* we have no preview icon but the thumbnail should be ready. determine
-           * the filename of the thumbnail */
-          thumbnail_path = thunar_file_get_thumbnail_path (file);
-
-          /* check if we have a valid path */
-          if (thumbnail_path != NULL)
-            {
-              /* try to load the thumbnail */
-              icon = thunar_icon_factory_load_from_file (factory, thumbnail_path, icon_size);
-            }
         }
     }
 
diff -rNaud Thunar-1.8.1/thunar/thunar-thumbnailer.c Thunar-1.8.1-NEW/thunar/thunar-thumbnailer.c
--- Thunar-1.8.1/thunar/thunar-thumbnailer.c	2018-03-23 03:15:01.000000000 +0100
+++ Thunar-1.8.1-NEW/thunar/thunar-thumbnailer.c	2018-08-21 17:30:14.669070767 +0200
@@ -328,8 +328,8 @@
    * processed (and awaiting to be refreshed) */
   for (lp = job->files; lp != NULL; lp = lp->next)
     {
-      /* the icon factory only loads icons for regular files */
-      if (!thunar_file_is_regular (lp->data))
+      /* the icon factory only loads icons for regular files & folders */
+      if (!thunar_file_is_regular (lp->data) && !thunar_file_is_directory (lp->data))
         {
           thunar_file_set_thumb_state (lp->data, THUNAR_FILE_THUMB_STATE_NONE);
           continue;