diff --git a/db/access.php b/db/access.php
index feaa696a..a0329387 100644
--- a/db/access.php
+++ b/db/access.php
@@ -48,7 +48,7 @@
                 'captype' => 'write',
                 'contextlevel' => CONTEXT_MODULE,
                 'archetypes' => [
-                        'guest' => CAP_PROHIBIT,
+                        'guest' => CAP_PREVENT,
                         'student' => CAP_ALLOW,
                         'teacher' => CAP_ALLOW,
                         'editingteacher' => CAP_ALLOW,
@@ -62,7 +62,7 @@
                 'captype' => 'write',
                 'contextlevel' => CONTEXT_MODULE,
                 'archetypes' => [
-                        'guest' => CAP_PROHIBIT,
+                        'guest' => CAP_PREVENT,
                         'student' => CAP_PREVENT,
                         'teacher' => CAP_ALLOW,
                         'editingteacher' => CAP_ALLOW,
@@ -76,7 +76,7 @@
                 'captype' => 'read',
                 'contextlevel' => CONTEXT_MODULE,
                 'archetypes' => [
-                        'guest' => CAP_PROHIBIT,
+                        'guest' => CAP_PREVENT,
                         'student' => CAP_PREVENT,
                         'teacher' => CAP_ALLOW,
                         'editingteacher' => CAP_ALLOW,
@@ -90,8 +90,8 @@
                 'captype' => 'write',
                 'contextlevel' => CONTEXT_COURSE,
                 'archetypes' => [
-                        'guest' => CAP_PROHIBIT,
-                        'student' => CAP_PROHIBIT,
+                        'guest' => CAP_PREVENT,
+                        'student' => CAP_PREVENT,
                         'teacher' => CAP_PREVENT,
                         'editingteacher' => CAP_ALLOW,
                         'coursecreator' => CAP_ALLOW,
@@ -105,8 +105,8 @@
                 'captype' => 'write',
                 'contextlevel' => CONTEXT_MODULE,
                 'archetypes' => [
-                        'guest' => CAP_PROHIBIT,
-                        'student' => CAP_PROHIBIT,
+                        'guest' => CAP_PREVENT,
+                        'student' => CAP_PREVENT,
                         'teacher' => CAP_PREVENT,
                         'editingteacher' => CAP_ALLOW,
                         'coursecreator' => CAP_ALLOW,
@@ -119,9 +119,9 @@
                 'captype' => 'write',
                 'contextlevel' => CONTEXT_MODULE,
                 'archetypes' => [
-                        'guest' => CAP_PROHIBIT,
-                        'student' => CAP_PROHIBIT,
-                        'teacher' => CAP_PROHIBIT,
+                        'guest' => CAP_PREVENT,
+                        'student' => CAP_PREVENT,
+                        'teacher' => CAP_PREVENT,
                         'editingteacher' => CAP_ALLOW,
                         'coursecreator' => CAP_ALLOW,
                         'manager' => CAP_ALLOW,