diff --git a/mod/lesson/action/continue.php b/mod/lesson/action/continue.php
index e6a1dd0ab0b..cf000ea32ca 100644
--- a/mod/lesson/action/continue.php
+++ b/mod/lesson/action/continue.php
@@ -88,7 +88,9 @@
             $studentanswer = s($useranswer);
             break;
          case LESSON_SHORTANSWER :
-            if (!$useranswer = $_POST['answer']) {
+            if (isset($_POST['answer'])) {
+                $useranswer = $_POST['answer'];
+            } else {
                 $noanswer = true;
                 break;
             }            
diff --git a/mod/lesson/action/updatepage.php b/mod/lesson/action/updatepage.php
index 576c740bede..c22a3078756 100644
--- a/mod/lesson/action/updatepage.php
+++ b/mod/lesson/action/updatepage.php
@@ -84,7 +84,7 @@
         for ($i = 0; $i < $lesson->maxanswers; $i++) {
             // strip tags because the editor gives <p><br />...
             // also save any answers where the editor is (going to be) used
-            if ((!empty($form->answer[$i]) and trim(strip_tags($form->answer[$i]))) or isset($form->answereditor[$i]) or isset($form->responseeditor[$i])) {
+            if ((isset($form->answer[$i]) and (trim(strip_tags($form->answer[$i]))) != '') or isset($form->answereditor[$i]) or isset($form->responseeditor[$i])) {
                 if ($form->answerid[$i]) {
                     $oldanswer = new stdClass;
                     $oldanswer->id = clean_param($form->answerid[$i], PARAM_INT);