diff --git a/lib/moodlelib.php b/lib/moodlelib.php
index 6591795fcca..910f8999931 100644
--- a/lib/moodlelib.php
+++ b/lib/moodlelib.php
@@ -5842,15 +5842,15 @@ function get_max_upload_file_size($sitebytes=0, $coursebytes=0, $modulebytes=0)
         }
     }
 
-    if ($sitebytes and $sitebytes < $minimumsize) {
+    if (($sitebytes > 0) and ($sitebytes < $minimumsize)) {
         $minimumsize = $sitebytes;
     }
 
-    if ($coursebytes and $coursebytes < $minimumsize) {
+    if (($coursebytes > 0) and ($coursebytes < $minimumsize)) {
         $minimumsize = $coursebytes;
     }
 
-    if ($modulebytes and $modulebytes < $minimumsize) {
+    if (($modulebytes > 0) and ($modulebytes < $minimumsize)) {
         $minimumsize = $modulebytes;
     }
 
diff --git a/repository/filepicker.php b/repository/filepicker.php
index 568cd6d1519..fd16e6676ca 100644
--- a/repository/filepicker.php
+++ b/repository/filepicker.php
@@ -89,11 +89,9 @@ if ($repo_id) {
 }
 
 $context = context::instance_by_id($contextid);
-$moodle_maxbytes = get_user_max_upload_file_size($context, $CFG->maxbytes, $course->maxbytes);
-// to prevent maxbytes greater than moodle maxbytes setting
-if (($maxbytes <= 0) || ($maxbytes >= $moodle_maxbytes)) {
-    $maxbytes = $moodle_maxbytes;
-}
+
+// Make sure maxbytes passed is within site filesize limits.
+$maxbytes = get_user_max_upload_file_size($context, $CFG->maxbytes, $course->maxbytes, $maxbytes);
 
 $params = array('ctx_id' => $contextid, 'itemid' => $itemid, 'env' => $env, 'course'=>$courseid, 'maxbytes'=>$maxbytes, 'maxfiles'=>$maxfiles, 'subdirs'=>$subdirs, 'sesskey'=>sesskey());
 $params['action'] = 'browse';
diff --git a/repository/repository_ajax.php b/repository/repository_ajax.php
index ed159e54355..98701a581ac 100644
--- a/repository/repository_ajax.php
+++ b/repository/repository_ajax.php
@@ -78,15 +78,13 @@ $repo = repository::get_repository_by_id($repo_id, $contextid, $repooptions);
 
 // Check permissions
 $repo->check_capability();
+
 $coursemaxbytes = 0;
 if (!empty($course)) {
     $coursemaxbytes = $course->maxbytes;
 }
-$moodle_maxbytes = get_user_max_upload_file_size($context, $CFG->maxbytes, $coursemaxbytes);
-// to prevent maxbytes greater than moodle maxbytes setting
-if (($maxbytes <= 0) || ($maxbytes >= $moodle_maxbytes)) {
-    $maxbytes = $moodle_maxbytes;
-}
+// Make sure maxbytes passed is within site filesize limits.
+$maxbytes = get_user_max_upload_file_size($context, $CFG->maxbytes, $coursemaxbytes, $maxbytes);
 
 // Wait as long as it takes for this script to finish
 set_time_limit(0);