diff --git a/.appveyor.yml b/.appveyor.yml
index a729b034d9..1e2bc1c184 100644
--- a/.appveyor.yml
+++ b/.appveyor.yml
@@ -7,18 +7,18 @@ services:
 
 environment:
   matrix:
-#  - db: mssql
-#    db_version: sql2012sp1
-#    php: 7.0
-#  - db: mssql
-#    db_version: sql2014
-#    php: 7.0
-#  - db: mssql
-#    db_version: sql2016
-#    php: 7.0
   - db: mssql
-    db_version: sql2017
-    php: 7.1
+    db_version: sql2012sp1
+    php: 7.0
+  - db: mssql
+    db_version: sql2014
+    php: 7.0
+  - db: mssql
+    db_version: sql2016
+    php: 7.0
+#  - db: mssql
+#    db_version: sql2017
+#    php: 7.1
 #  - db: mariadb
 #    php: 7.1
 #  - db: mysqli
@@ -114,6 +114,10 @@ before_test:
       # Install PhantomJS
       cinst -y phantomjs
       Start-Process "phantomjs" "--webdriver=8910" | Out-Null
+  - ps: |
+      cd c:\projects\phpbb\phpBB
+      (Get-Content c:\projects\phpbb\phpBB\web.config).replace("<configuration>", "<configuration>`n`t<system.web>`n`t`t<customErrors mode=`"Off`"/>`n`t</system.web>") | Set-Content c:\projects\phpbb\phpBB\web.config
+      (Get-Content c:\projects\phpbb\phpBB\web.config).replace("`t</system.webServer>", "`t`t<httpErrors errorMode=`"Detailed`" />`n`t</system.webServer>") | Set-Content c:\projects\phpbb\phpBB\web.config
   - cd c:\projects\phpbb\phpBB
   - php ..\composer.phar install
   - choco install -y urlrewrite
diff --git a/tests/test_framework/phpbb_functional_test_case.php b/tests/test_framework/phpbb_functional_test_case.php
index a63d5dc5ec..e1daa4558a 100644
--- a/tests/test_framework/phpbb_functional_test_case.php
+++ b/tests/test_framework/phpbb_functional_test_case.php
@@ -918,7 +918,7 @@ class phpbb_functional_test_case extends phpbb_test_case
 		if ($status_code != self::$client->getResponse()->getStatus() &&
 			preg_match('/^5[0-9]{2}/', self::$client->getResponse()->getStatus()))
 		{
-			self::fail('Encountered unexpected server error:\n' . self::$client->getResponse()->getContent());
+			self::fail("Encountered unexpected server error:\n" . self::$client->getResponse()->getContent());
 		}
 		self::assertEquals($status_code, self::$client->getResponse()->getStatus(), 'HTTP status code does not match');
 	}