diff --git a/mod/assignment/lib.php b/mod/assignment/lib.php
index 82bbf46db07..3d1e94700ae 100644
--- a/mod/assignment/lib.php
+++ b/mod/assignment/lib.php
@@ -1878,7 +1878,7 @@ class assignment_base {
     function get_submissions($sort='', $dir='DESC') {
         return assignment_get_all_submissions($this->assignment, $sort, $dir);
     }
-    
+
     /**
      * Counts all complete (real) assignment submissions by enrolled students
      *
@@ -3480,7 +3480,7 @@ function assignment_get_unmailed_submissions($starttime, $endtime) {
 
 /**
  * Counts all complete (real) assignment submissions by enrolled students for the given course modeule.
- * 
+ *
  * @deprecated                         Since Moodle 2.2 MDL-abc - Please do not use this function any more.
  * @param  cm_info $cm                 The course module that we wish to perform the count on.
  * @param  int     $groupid (optional) If nonzero then count is restricted to this group
@@ -3490,18 +3490,18 @@ function assignment_count_real_submissions($cm, $groupid=0) {
     global $CFG, $DB;
 
     // Grab the assignment type for the given course module
-    $assignmenttype = $DB->get_field($cm->modname, 'assignmenttype', array('id' => $cm->instance));
+    $assignmenttype = $DB->get_field($cm->modname, 'assignmenttype', array('id' => $cm->instance), MUST_EXIST);
 
     // Create the expected class file path and class name for the returned assignemnt type
     $filename = "{$CFG->dirroot}/mod/assignment/type/{$assignmenttype}/assignment.class.php";
     $classname = "assignment_{$assignmenttype}";
 
     // If the file exists and the class is not already loaded we require the class file
-    if (file_exists($file) && !class_exists($class)) {
-        require_once($file);
+    if (file_exists($filename) && !class_exists($classname)) {
+        require_once($filename);
     }
     // If the required class is still not loaded then we revert to assignment base
-    if (!class_exists($class)) {
+    if (!class_exists($classname)) {
         $classname = 'assignment_base';
     }
     $instance = new $classname;
diff --git a/mod/assignment/type/upload/assignment.class.php b/mod/assignment/type/upload/assignment.class.php
index 15319d85ede..86bb7943ace 100644
--- a/mod/assignment/type/upload/assignment.class.php
+++ b/mod/assignment/type/upload/assignment.class.php
@@ -405,7 +405,6 @@ class assignment_upload extends assignment_base {
      * @return int          The number of submissions
      */
     function count_real_submissions($groupid=0) {
-        global $CFG;
         global $DB;
 
         // Grab the context assocated with our course module
diff --git a/mod/assignment/type/uploadsingle/assignment.class.php b/mod/assignment/type/uploadsingle/assignment.class.php
index 706489e96f2..08cd0068468 100644
--- a/mod/assignment/type/uploadsingle/assignment.class.php
+++ b/mod/assignment/type/uploadsingle/assignment.class.php
@@ -111,7 +111,6 @@ class assignment_uploadsingle extends assignment_base {
      * @return int          The number of submissions
      */
     function count_real_submissions($groupid=0) {
-        global $CFG;
         global $DB;
 
         // Grab the context assocated with our course module