diff --git a/ext/mysqli/tests/bug34810.phpt b/ext/mysqli/tests/bug34810.phpt
index 19a7e589bbf..998d9f015b3 100644
--- a/ext/mysqli/tests/bug34810.phpt
+++ b/ext/mysqli/tests/bug34810.phpt
@@ -55,7 +55,7 @@ object(mysqli)#%d (%d) {
   [%u|b%"connect_errno"]=>
   int(0)
   [%u|b%"connect_error"]=>
-  %unicode|string%(0) ""
+  NULL
   [%u|b%"errno"]=>
   int(0)
   [%u|b%"error"]=>
@@ -91,7 +91,7 @@ object(mysqli)#%d (%d) {
   [%u|b%"connect_errno"]=>
   int(0)
   [%u|b%"connect_error"]=>
-  %unicode|string%(0) ""
+  NULL
   [%u|b%"errno"]=>
   int(0)
   [%u|b%"error"]=>
diff --git a/ext/mysqli/tests/mysqli_class_mysqli_interface.phpt b/ext/mysqli/tests/mysqli_class_mysqli_interface.phpt
index ad914b73432..b86f69c445b 100644
--- a/ext/mysqli/tests/mysqli_class_mysqli_interface.phpt
+++ b/ext/mysqli/tests/mysqli_class_mysqli_interface.phpt
@@ -276,6 +276,6 @@ setting mysqli->unknown, mysqli_unknown = '13'
 setting mysqli->unknown, mysqli_unknown = 'friday'
 
 Access hidden properties for MYSLQI_STATUS_INITIALIZED (TODO documentation):
-mysqli->connect_error = ''/%unicode|string% (''/%unicode|string%)
+mysqli->connect_error = ''/NULL (''/NULL)
 mysqli->connect_errno = '0'/integer ('0'/integer)
 done!
\ No newline at end of file
diff --git a/ext/mysqli/tests/mysqli_connect_error.phpt b/ext/mysqli/tests/mysqli_connect_error.phpt
index dc4db6af58a..79ac3f1f795 100644
--- a/ext/mysqli/tests/mysqli_connect_error.phpt
+++ b/ext/mysqli/tests/mysqli_connect_error.phpt
@@ -21,8 +21,8 @@ require_once('skipifconnectfailure.inc');
 		printf("[002] Cannot connect to the server using host=%s, user=%s, passwd=***, dbname=%s, port=%s, socket=%s\n",
 			$host, $user, $db, $port, $socket);
 
-	if ('' !== ($tmp = mysqli_connect_error()))
-		printf("[003] Expecting string/'', got %s/%s\n", gettype($tmp), $tmp);
+	if (NULL !== ($tmp = mysqli_connect_error()))
+		printf("[003] Expecting NULL, got %s/%s\n", gettype($tmp), $tmp);
 
 	mysqli_close($link);
 
diff --git a/ext/mysqli/tests/mysqli_kill.phpt b/ext/mysqli/tests/mysqli_kill.phpt
index f680a68137d..5706adf46d4 100644
--- a/ext/mysqli/tests/mysqli_kill.phpt
+++ b/ext/mysqli/tests/mysqli_kill.phpt
@@ -91,7 +91,7 @@ object(mysqli)#%d (%d) {
   [%u|b%"connect_errno"]=>
   int(0)
   [%u|b%"connect_error"]=>
-  %unicode|string%(0) ""
+  NULL
   [%u|b%"errno"]=>
   int(2006)
   [%u|b%"error"]=>