diff --git a/question/format/xml/format.php b/question/format/xml/format.php
index cb6b56cc0ac..e32d1ace76a 100644
--- a/question/format/xml/format.php
+++ b/question/format/xml/format.php
@@ -772,8 +772,10 @@ class qformat_xml extends qformat_default {
                 array('#', 'responserequired', 0, '#'), 1);
         $qo->minwordlimit = $this->getpath($question,
                 array('#', 'minwordlimit', 0, '#'), null);
+        $qo->minwordenabled = !empty($qo->minwordlimit);
         $qo->maxwordlimit = $this->getpath($question,
                 array('#', 'maxwordlimit', 0, '#'), null);
+        $qo->maxwordenabled = !empty($qo->maxwordlimit);
         $qo->attachments = $this->getpath($question,
                 array('#', 'attachments', 0, '#'), 0);
         $qo->attachmentsrequired = $this->getpath($question,
diff --git a/question/format/xml/tests/xmlformat_test.php b/question/format/xml/tests/xmlformat_test.php
index 740db03d52b..3de9b313c28 100644
--- a/question/format/xml/tests/xmlformat_test.php
+++ b/question/format/xml/tests/xmlformat_test.php
@@ -407,7 +407,9 @@ END;
         $expectedq->responserequired = 1;
         $expectedq->responsefieldlines = 15;
         $expectedq->minwordlimit = null;
+        $expectedq->minwordenabled = false;
         $expectedq->maxwordlimit = null;
+        $expectedq->maxwordenabled = false;
         $expectedq->attachments = 0;
         $expectedq->attachmentsrequired = 0;
         $expectedq->maxbytes = 0;
@@ -470,7 +472,9 @@ END;
         $expectedq->responserequired = 0;
         $expectedq->responsefieldlines = 42;
         $expectedq->minwordlimit = null;
+        $expectedq->minwordenabled = false;
         $expectedq->maxwordlimit = null;
+        $expectedq->maxwordenabled = false;
         $expectedq->attachments = -1;
         $expectedq->attachmentsrequired = 1;
         $expectedq->maxbytes = 0;
@@ -537,7 +541,9 @@ END;
         $expectedq->responserequired = 0;
         $expectedq->responsefieldlines = 42;
         $expectedq->minwordlimit = 10;
+        $expectedq->minwordenabled = true;
         $expectedq->maxwordlimit = 20;
+        $expectedq->maxwordenabled = true;
         $expectedq->attachments = -1;
         $expectedq->attachmentsrequired = 1;
         $expectedq->maxbytes = 52428800; // 50MB.
diff --git a/question/type/essay/tests/behat/edit_min_max_fields.feature b/question/type/essay/tests/behat/edit_min_max_fields.feature
index 44105c59a41..e73f93743a8 100644
--- a/question/type/essay/tests/behat/edit_min_max_fields.feature
+++ b/question/type/essay/tests/behat/edit_min_max_fields.feature
@@ -18,7 +18,7 @@ I need to choose the appropriate minimum and/or maximum number of words for inpu
       | Course       | C1        | Test questions |
     And the following "questions" exist:
       | questioncategory | qtype | name          | template | minwordlimit | maxwordlimit |
-      | Test questions   | essay | essay-min-max | editor   | null         | null         |
+      | Test questions   | essay | essay-min-max | editor   | 0            | 0            |
     Given I log in as "teacher1"
     And I am on "Course 1" course homepage
     And I navigate to "Question bank" in current page administration
@@ -56,3 +56,27 @@ I need to choose the appropriate minimum and/or maximum number of words for inpu
     When I set the field "Require text" to "Text input is optional"
     Then I should not see "Minimum word limit"
     And I should not see "Minimum word limit"
+
+  @javascript
+  Scenario: Minimum/Maximum word limit can be unset after being set.
+    Given I choose "Edit question" action for "essay-min-max" in the question bank
+    When I set the following fields to these values:
+      | minwordenabled  | 1   |
+      | id_minwordlimit | 100 |
+      | maxwordenabled  | 1   |
+      | id_maxwordlimit | 200 |
+    And I click on "Save changes and continue editing" "button"
+    Then the following fields match these values:
+      | minwordenabled  | 1   |
+      | id_minwordlimit | 100 |
+      | maxwordenabled  | 1   |
+      | id_maxwordlimit | 200 |
+    And I set the following fields to these values:
+      | minwordenabled  | 0 |
+      | maxwordenabled  | 0 |
+    And I click on "Save changes and continue editing" "button"
+    And the following fields match these values:
+      | minwordenabled  | 0 |
+      | id_minwordlimit |   |
+      | maxwordenabled  | 0 |
+      | id_maxwordlimit |   |
diff --git a/question/type/essay/tests/behat/import.feature b/question/type/essay/tests/behat/import.feature
index 195b78cb244..e365569e370 100644
--- a/question/type/essay/tests/behat/import.feature
+++ b/question/type/essay/tests/behat/import.feature
@@ -28,3 +28,5 @@ Feature: Test importing Essay questions
     And I should see "Write an essay with 500 words."
     And I press "Continue"
     And I should see "essay-001"
+    And I choose "Edit question" action for "essay-001" in the question bank
+    And the field "id_maxwordlimit" matches value "20"
diff --git a/question/type/essay/tests/fixtures/testquestion.moodle.xml b/question/type/essay/tests/fixtures/testquestion.moodle.xml
index a6fb84bcbea..811a687759b 100644
--- a/question/type/essay/tests/fixtures/testquestion.moodle.xml
+++ b/question/type/essay/tests/fixtures/testquestion.moodle.xml
@@ -26,7 +26,7 @@
     <responserequired>1</responserequired>
     <responsefieldlines>15</responsefieldlines>
     <minwordlimit></minwordlimit>
-    <maxwordlimit></maxwordlimit>
+    <maxwordlimit>20</maxwordlimit>
     <attachments>0</attachments>
     <attachmentsrequired>0</attachmentsrequired>
     <maxbytes>0</maxbytes>