diff --git a/course/dndupload.js b/course/dndupload.js
index 1a1d4343a26..6d52635c291 100644
--- a/course/dndupload.js
+++ b/course/dndupload.js
@@ -743,7 +743,9 @@ M.course_dndupload = {
         var self = this;
 
         if (file.size > this.maxbytes) {
-            alert("'"+file.name+"' "+M.util.get_string('filetoolarge', 'moodle'));
+            new M.core.alert({
+                message: "'" + file.name + "' " + M.util.get_string('filetoolarge', 'moodle')
+            });
             return;
         }
 
@@ -777,11 +779,11 @@ M.course_dndupload = {
                         } else {
                             // Error - remove the dummy element
                             resel.parent.removeChild(resel.li);
-                            alert(result.error);
+                            new M.core.alert({message: result.error});
                         }
                     }
                 } else {
-                    alert(M.util.get_string('servererror', 'moodle'));
+                    new M.core.alert({message: M.util.get_string('servererror', 'moodle')});
                 }
             }
         };
@@ -1002,11 +1004,11 @@ M.course_dndupload = {
                         } else {
                             // Error - remove the dummy element
                             resel.parent.removeChild(resel.li);
-                            alert(result.error);
+                            new M.core.alert({message: result.error});
                         }
                     }
                 } else {
-                    alert(M.util.get_string('servererror', 'moodle'));
+                    new M.core.alert({message: M.util.get_string('servererror', 'moodle')});
                 }
             }
         };