diff --git a/course/classes/category.php b/course/classes/category.php
index a1e20c22a39..ba631fd4fcd 100644
--- a/course/classes/category.php
+++ b/course/classes/category.php
@@ -1600,7 +1600,10 @@ class core_course_category implements renderable, cacheable_object, IteratorAggr
                 }
                 // Prepare the list of core_course_list_element objects.
                 foreach ($ids as $id) {
-                    $courses[$id] = new core_course_list_element($records[$id]);
+                    // If a course is deleted after we got the cache entry it may not exist in the database anymore.
+                    if (!empty($records[$id])) {
+                        $courses[$id] = new core_course_list_element($records[$id]);
+                    }
                 }
             }
             return $courses;
@@ -1810,7 +1813,10 @@ class core_course_category implements renderable, cacheable_object, IteratorAggr
                 }
                 // Prepare the list of core_course_list_element objects.
                 foreach ($ids as $id) {
-                    $courses[$id] = new core_course_list_element($records[$id]);
+                    // If a course is deleted after we got the cache entry it may not exist in the database anymore.
+                    if (!empty($records[$id])) {
+                        $courses[$id] = new core_course_list_element($records[$id]);
+                    }
                 }
             }
             return $courses;
diff --git a/course/tests/category_test.php b/course/tests/category_test.php
index 54899398c73..8d8b26be765 100644
--- a/course/tests/category_test.php
+++ b/course/tests/category_test.php
@@ -1080,4 +1080,26 @@ class core_course_category_testcase extends advanced_testcase {
         }
         return $draftid;
     }
+
+    /**
+     * This test ensures that is the list of courses in a category can be retrieved while a course is being deleted.
+     */
+    public function test_get_courses_during_delete() {
+        global $DB;
+        $category = self::getDataGenerator()->create_category();
+        $course = self::getDataGenerator()->create_course(['category' => $category->id]);
+        $othercourse = self::getDataGenerator()->create_course(['category' => $category->id]);
+        $coursecategory = core_course_category::get($category->id);
+        // Get a list of courses before deletion to populate the cache.
+        $originalcourses = $coursecategory->get_courses();
+        $this->assertCount(2, $originalcourses);
+        $this->assertArrayHasKey($course->id, $originalcourses);
+        $this->assertArrayHasKey($othercourse->id, $originalcourses);
+        // Simulate the course deletion process being part way though.
+        $DB->delete_records('course', ['id' => $course->id]);
+        // Get the list of courses while a deletion is in progress.
+        $courses = $coursecategory->get_courses();
+        $this->assertCount(1, $courses);
+        $this->assertArrayHasKey($othercourse->id, $courses);
+    }
 }
diff --git a/lib/moodlelib.php b/lib/moodlelib.php
index 6f4a6c08927..cb91da2f556 100644
--- a/lib/moodlelib.php
+++ b/lib/moodlelib.php
@@ -5245,6 +5245,9 @@ function remove_course_contents($courseid, $showfeedback = true, array $options
         echo $OUTPUT->notification($strdeleted.get_string('type_block_plural', 'plugin'), 'notifysuccess');
     }
 
+    $DB->set_field('course_modules', 'deletioninprogress', '1', ['course' => $courseid]);
+    rebuild_course_cache($courseid, true);
+
     // Get the list of all modules that are properly installed.
     $allmodules = $DB->get_records_menu('modules', array(), '', 'name, id');
 
@@ -5287,6 +5290,7 @@ function remove_course_contents($courseid, $showfeedback = true, array $options
                         // Delete cm and its context - orphaned contexts are purged in cron in case of any race condition.
                         context_helper::delete_instance(CONTEXT_MODULE, $cm->id);
                         $DB->delete_records('course_modules', array('id' => $cm->id));
+                        rebuild_course_cache($cm->course, true);
                     }
                 }
             }
@@ -5323,6 +5327,7 @@ function remove_course_contents($courseid, $showfeedback = true, array $options
         }
         context_helper::delete_instance(CONTEXT_MODULE, $cm->id);
         $DB->delete_records('course_modules', array('id' => $cm->id));
+        rebuild_course_cache($cm->course, true);
     }
 
     if ($showfeedback) {