diff --git a/tests/BlogCategoryTest.php b/tests/BlogCategoryTest.php
index caf4b4a..1cc4aa0 100755
--- a/tests/BlogCategoryTest.php
+++ b/tests/BlogCategoryTest.php
@@ -52,7 +52,7 @@ class BlogCategoryTest extends FunctionalTest
         $member = Security::getCurrentUser();
 
         if ($member) {
-            $member->logout();
+            Security::setCurrentUser(null);
         }
 
         $this->objFromFixture(BlogPost::class, 'FirstBlogPost');
diff --git a/tests/BlogPostFilterTest.php b/tests/BlogPostFilterTest.php
index d82eeaf..da3efa7 100755
--- a/tests/BlogPostFilterTest.php
+++ b/tests/BlogPostFilterTest.php
@@ -42,7 +42,7 @@ class BlogPostFilterTest extends SapphireTest
         $member = Security::getCurrentUser();
 
         if ($member) {
-            $member->logout();
+            Security::setCurrentUser(null);
         }
 
         /**
diff --git a/tests/BlogTagTest.php b/tests/BlogTagTest.php
index be4c982..237572b 100755
--- a/tests/BlogTagTest.php
+++ b/tests/BlogTagTest.php
@@ -10,6 +10,7 @@ use SilverStripe\Dev\FunctionalTest;
 use SilverStripe\ORM\FieldType\DBDatetime;
 use SilverStripe\ORM\ValidationException;
 use SilverStripe\Security\Member;
+use SilverStripe\Security\Security;
 
 /**
  * @mixin PHPUnit_Framework_TestCase
@@ -51,7 +52,7 @@ class BlogTagTest extends FunctionalTest
         $member = Security::getCurrentUser();
 
         if ($member) {
-            $member->logout();
+            Security::setCurrentUser(null);
         }
 
         $this->objFromFixture(BlogPost::class, 'FirstBlogPost');
diff --git a/tests/BlogTest.php b/tests/BlogTest.php
index 6e0ef7a..a942267 100755
--- a/tests/BlogTest.php
+++ b/tests/BlogTest.php
@@ -62,7 +62,7 @@ class BlogTest extends SapphireTest
         $member = Security::getCurrentUser();
 
         if ($member) {
-            $member->logout();
+            Security::setCurrentUser(null);
         }
 
         /**
@@ -86,7 +86,7 @@ class BlogTest extends SapphireTest
         $member = Security::getCurrentUser();
 
         if ($member) {
-            $member->logout();
+            Security::setCurrentUser(null);
         }
 
         /**