diff --git a/mod/workshop/lib.php b/mod/workshop/lib.php
index a266e1e7393..6fb41e3e2e7 100644
--- a/mod/workshop/lib.php
+++ b/mod/workshop/lib.php
@@ -82,11 +82,11 @@ function workshop_add_instance(stdclass $workshop) {
     $workshop->evaluation            = 'best';
 
     if (isset($workshop->gradinggradepass)) {
-        $workshop->gradinggradepass = unformat_float($workshop->gradinggradepass);
+        $workshop->gradinggradepass = (float)unformat_float($workshop->gradinggradepass);
     }
 
     if (isset($workshop->submissiongradepass)) {
-        $workshop->submissiongradepass = unformat_float($workshop->submissiongradepass);
+        $workshop->submissiongradepass = (float)unformat_float($workshop->submissiongradepass);
     }
 
     // insert the new record so we get the id
@@ -150,11 +150,11 @@ function workshop_update_instance(stdclass $workshop) {
     $workshop->phaseswitchassessment = (int)!empty($workshop->phaseswitchassessment);
 
     if (isset($workshop->gradinggradepass)) {
-        $workshop->gradinggradepass = unformat_float($workshop->gradinggradepass);
+        $workshop->gradinggradepass = (float)unformat_float($workshop->gradinggradepass);
     }
 
     if (isset($workshop->submissiongradepass)) {
-        $workshop->submissiongradepass = unformat_float($workshop->submissiongradepass);
+        $workshop->submissiongradepass = (float)unformat_float($workshop->submissiongradepass);
     }
 
     // todo - if the grading strategy is being changed, we may want to replace all aggregated peer grades with nulls
diff --git a/mod/workshop/mod_form.php b/mod/workshop/mod_form.php
index 7aee3393ba4..3f93958f534 100644
--- a/mod/workshop/mod_form.php
+++ b/mod/workshop/mod_form.php
@@ -371,9 +371,9 @@ class mod_workshop_mod_form extends moodleform_mod {
         }
 
         // Check that the submission grade pass is a valid number.
-        if (isset($data['submissiongradepass'])) {
+        if (!empty($data['submissiongradepass'])) {
             $submissiongradefloat = unformat_float($data['submissiongradepass'], true);
-            if ($submissiongradefloat === false || $submissiongradefloat === null) {
+            if ($submissiongradefloat === false) {
                 $errors['submissiongradepass'] = get_string('err_numeric', 'form');
             } else {
                 if ($submissiongradefloat > $data['grade']) {
@@ -383,9 +383,9 @@ class mod_workshop_mod_form extends moodleform_mod {
         }
 
         // Check that the grade pass is a valid number.
-        if (isset($data['gradinggradepass'])) {
+        if (!empty($data['gradinggradepass'])) {
             $gradepassfloat = unformat_float($data['gradinggradepass'], true);
-            if ($gradepassfloat === false || $gradepassfloat === null) {
+            if ($gradepassfloat === false) {
                 $errors['gradinggradepass'] = get_string('err_numeric', 'form');
             } else {
                 if ($gradepassfloat > $data['gradinggrade']) {
diff --git a/mod/workshop/tests/behat/grade_to_pass.feature b/mod/workshop/tests/behat/grade_to_pass.feature
new file mode 100644
index 00000000000..da72a7a3ece
--- /dev/null
+++ b/mod/workshop/tests/behat/grade_to_pass.feature
@@ -0,0 +1,91 @@
+@mod @mod_workshop
+Feature: Setting grades to pass via workshop editing form
+  In order to define grades to pass
+  As a teacher
+  I can set them in the workshop settings form, without the need to go to the gradebook
+
+  Background:
+    Given the following "users" exist:
+      | username | firstname | lastname | email                |
+      | teacher1 | Terry1    | Teacher1 | teacher1@example.com |
+    And the following "courses" exist:
+      | fullname  | shortname |
+      | Course1   | c1        |
+    And the following "course enrolments" exist:
+      | user     | course | role           |
+      | teacher1 | c1     | editingteacher |
+
+  Scenario: Adding a new workshop with grade to pass field set
+    Given I log in as "teacher1"
+    And I follow "Course1"
+    And I turn editing mode on
+    When I add a "Workshop" to section "1" and I fill the form with:
+      | Workshop name | Awesome workshop |
+      | Description | Grades to pass are set here |
+      | Submission grade to pass | 45   |
+      | Assessment grade to pass | 10.5 |
+    Then I should not see "Adding a new Workshop"
+    And I follow "Awesome workshop"
+    And I navigate to "Edit settings" node in "Workshop administration"
+    And the field "Submission grade to pass" matches value "45.00"
+    And the field "Assessment grade to pass" matches value "10.50"
+
+  Scenario: Adding a new workshop with grade to pass fields left empty
+    Given I log in as "teacher1"
+    And I follow "Course1"
+    And I turn editing mode on
+    When I add a "Workshop" to section "1" and I fill the form with:
+      | Workshop name | Another awesome workshop |
+      | Description | No grades to pass are set here |
+      | Submission grade to pass |    |
+      | Assessment grade to pass |    |
+    Then I should not see "Adding a new Workshop"
+    And I follow "Another awesome workshop"
+    And I navigate to "Edit settings" node in "Workshop administration"
+    And the field "Submission grade to pass" matches value "0.00"
+    And the field "Assessment grade to pass" matches value "0.00"
+
+  Scenario: Adding a new workshop with non-numeric value of a grade to pass
+    Given I log in as "teacher1"
+    And I follow "Course1"
+    And I turn editing mode on
+    When I add a "Workshop" to section "1" and I fill the form with:
+      | Workshop name | Almost awesome workshop |
+      | Description | Invalid grade to pass is set here |
+      | Assessment grade to pass | You shall not pass! |
+    Then I should see "Adding a new Workshop"
+    And I should see "You must enter a number here"
+
+  Scenario: Adding a new workshop with invalid value of a grade to pass
+    Given I log in as "teacher1"
+    And I follow "Course1"
+    And I turn editing mode on
+    When I add a "Workshop" to section "1" and I fill the form with:
+      | Workshop name | Almost awesome workshop |
+      | Description | Invalid grade to pass is set here |
+      | Assessment grade to pass | 10000000 |
+    Then I should see "Adding a new Workshop"
+    And I should see "The grade to pass can not be greater than the maximum possible grade"
+
+  Scenario: Emptying grades to pass fields sets them to zero
+    Given I log in as "teacher1"
+    And I follow "Course1"
+    And I turn editing mode on
+    And I add a "Workshop" to section "1" and I fill the form with:
+      | Workshop name | Super awesome workshop |
+      | Description | Grade to pass are set and then unset here |
+      | Submission grade to pass | 59.99 |
+      | Assessment grade to pass | 0.000 |
+    And I should not see "Adding a new Workshop"
+    And I follow "Super awesome workshop"
+    And I navigate to "Edit settings" node in "Workshop administration"
+    And the field "Submission grade to pass" matches value "59.99"
+    And the field "Assessment grade to pass" matches value "0.00"
+    When I set the field "Submission grade to pass" to ""
+    And I set the field "Assessment grade to pass" to ""
+    And I press "Save and display"
+    Then I should not see "Adding a new Workshop"
+    And I follow "Super awesome workshop"
+    And I navigate to "Edit settings" node in "Workshop administration"
+    And the field "Submission grade to pass" matches value "0.00"
+    And the field "Assessment grade to pass" matches value "0.00"