diff --git a/db_central_columns.php b/db_central_columns.php
index 33078bf24d..71dac4ba03 100644
--- a/db_central_columns.php
+++ b/db_central_columns.php
@@ -156,7 +156,7 @@ if ($total_rows <= 0) {
             'The central list of columns for the current database is empty.'
         ) . '</fieldset>'
     );
-    $columnAdd = $centralColumns->getHtmlForAddCentralColumn($GLOBALS['dbi'], $total_rows, $pos, $db);
+    $columnAdd = $centralColumns->getHtmlForAddColumn($GLOBALS['dbi'], $total_rows, $pos, $db);
     $response->addHTML($columnAdd);
     exit;
 }
@@ -167,7 +167,7 @@ $table_navigation_html = $centralColumns->getHtmlForTableNavigation(
     $db
 );
 $response->addHTML($table_navigation_html);
-$columnAdd = $centralColumns->getHtmlForAddCentralColumn($GLOBALS['dbi'], $total_rows, $pos, $db);
+$columnAdd = $centralColumns->getHtmlForAddColumn($GLOBALS['dbi'], $total_rows, $pos, $db);
 $response->addHTML($columnAdd);
 $deleteRowForm = '<form method="post" id="del_form" action="db_central_columns.php">'
         . Url::getHiddenInputs(
@@ -195,7 +195,7 @@ $result = $centralColumns->getColumnsList(
 );
 $row_num = 0;
 foreach ($result as $row) {
-    $tableHtmlRow = $centralColumns->getHtmlForCentralColumnsTableRow(
+    $tableHtmlRow = $centralColumns->getHtmlForTableRow(
         $GLOBALS['dbi'],
         $GLOBALS['cfg']['MaxRows'],
         $GLOBALS['cfg']['CharEditing'],
diff --git a/libraries/classes/CentralColumns.php b/libraries/classes/CentralColumns.php
index cd39897dbc..7ed5d355cb 100644
--- a/libraries/classes/CentralColumns.php
+++ b/libraries/classes/CentralColumns.php
@@ -138,7 +138,7 @@ class CentralColumns
      *
      * @return array list of columns in central columns among given set of columns
      */
-    public function findExistingColNames(
+    private function findExistingColNames(
         DatabaseInterface $dbi,
         $user,
         $db,
@@ -177,7 +177,7 @@ class CentralColumns
      *
      * @return Message
      */
-    public function configErrorMessage()
+    private function configErrorMessage()
     {
         return Message::error(
             __(
@@ -200,7 +200,7 @@ class CentralColumns
      * @return string query string to insert the given column
      * with definition into central list
      */
-    public function getInsertQuery(
+    private function getInsertQuery(
         DatabaseInterface $dbi,
         $column,
         array $def,
@@ -798,7 +798,7 @@ class CentralColumns
      *
      * @return string html for table header in central columns multi edit page
      */
-    public function getEditTableHeader(array $headers)
+    private function getEditTableHeader(array $headers)
     {
         return Template::get(
             'database/central_columns/edit_table_header'
@@ -815,7 +815,7 @@ class CentralColumns
      *
      * @return string html dropdown for selecting table
      */
-    public function getHtmlForTableDropdown(DatabaseInterface $dbi, $db)
+    private function getHtmlForTableDropdown(DatabaseInterface $dbi, $db)
     {
         $dbi->selectDb($db);
         $tables = $dbi->getTables($db);
@@ -873,7 +873,7 @@ class CentralColumns
      *
      * @return string html to add a column in the central list
      */
-    public function getHtmlForAddCentralColumn(
+    public function getHtmlForAddColumn(
         DatabaseInterface $dbi,
         $total_rows,
         $pos,
@@ -921,7 +921,7 @@ class CentralColumns
      *
      * @return string html of a particular row in the central columns table.
      */
-    public function getHtmlForCentralColumnsTableRow(
+    public function getHtmlForTableRow(
         DatabaseInterface $dbi,
         $maxRows,
         $charEditing,
@@ -1104,7 +1104,7 @@ class CentralColumns
      *
      * @return string html of a particular row in the central columns table.
      */
-    public function getHtmlForCentralColumnsEditTableRow(
+    private function getHtmlForEditTableRow(
         DatabaseInterface $dbi,
         $maxRows,
         $charEditing,
@@ -1324,7 +1324,7 @@ class CentralColumns
      *
      * @return string html for table footer in central columns multi edit page
      */
-    public function getEditTableFooter()
+    private function getEditTableFooter()
     {
         $html_output = '<fieldset class="tblFooters">'
             . '<input type="submit" '
@@ -1341,7 +1341,7 @@ class CentralColumns
      *
      * @return void
      */
-    public function handleColumnExtra(array &$columns_list)
+    private function handleColumnExtra(array &$columns_list)
     {
         foreach ($columns_list as &$row) {
             $vals = explode(',', $row['col_extra']);
@@ -1537,7 +1537,7 @@ class CentralColumns
         $list_detail_cols = $this->findExistingColNames($dbi, $user, $selected_db, $columns_list, true);
         $row_num = 0;
         foreach ($list_detail_cols as $row) {
-            $tableHtmlRow = $this->getHtmlForCentralColumnsEditTableRow(
+            $tableHtmlRow = $this->getHtmlForEditTableRow(
                 $dbi,
                 $maxRows,
                 $charEditing,
diff --git a/test/classes/CentralColumnsTest.php b/test/classes/CentralColumnsTest.php
index 2d37eae346..891c61b6f6 100644
--- a/test/classes/CentralColumnsTest.php
+++ b/test/classes/CentralColumnsTest.php
@@ -14,6 +14,7 @@ use PhpMyAdmin\Types;
 use PhpMyAdmin\Url;
 use PhpMyAdmin\Util;
 use PHPUnit\Framework\TestCase;
+use ReflectionClass;
 
 $GLOBALS['server'] = 1;
 
@@ -131,6 +132,29 @@ class CentralColumnsTest extends TestCase
         $this->centralColumns = new CentralColumns();
     }
 
+    /**
+     * Call protected functions by setting visibility to public.
+     *
+     * @param string         $name   method name
+     * @param array          $params parameters for the invocation
+     * @param CentralColumns $object CentralColumns instance object
+     *
+     * @return mixed the output from the protected method.
+     */
+    private function callProtectedMethod(
+        $name,
+        array $params = [],
+        CentralColumns $object = null
+    ) {
+        $class = new ReflectionClass(CentralColumns::class);
+        $method = $class->getMethod($name);
+        $method->setAccessible(true);
+        return $method->invokeArgs(
+            $object !== null ? $object : $this->centralColumns,
+            $params
+        );
+    }
+
     /**
      * Test for getParams
      *
@@ -461,27 +485,39 @@ class CentralColumnsTest extends TestCase
         __('Collation'), __('Attributes'), __('Null'), __('A_I')
         );
         $this->assertContains(
-            $this->centralColumns->getEditTableHeader($header_cells), $result
+            $this->callProtectedMethod(
+                'getEditTableHeader',
+                [$header_cells]
+            ),
+            $result
         );
-        $list_detail_cols = $this->centralColumns->findExistingColNames(
-            $GLOBALS['dbi'],
-            $GLOBALS['cfg']['Server']['user'],
-            'phpmyadmin',
-            "'col1','col2'",
-            true
-        );
-        $this->assertContains(
-            $this->centralColumns->getHtmlForCentralColumnsEditTableRow(
+        $list_detail_cols = $this->callProtectedMethod(
+            'findExistingColNames',
+            [
                 $GLOBALS['dbi'],
-                $GLOBALS['cfg']['MaxRows'],
-                $GLOBALS['cfg']['CharEditing'],
-                $GLOBALS['cfg']['Server']['DisableIS'],
-                $list_detail_cols[0],
-                0
-            ), $result
+                $GLOBALS['cfg']['Server']['user'],
+                'phpmyadmin',
+                "'col1','col2'",
+                true,
+            ]
         );
         $this->assertContains(
-            $this->centralColumns->getEditTableFooter(), $result
+            $this->callProtectedMethod(
+                'getHtmlForEditTableRow',
+                [
+                    $GLOBALS['dbi'],
+                    $GLOBALS['cfg']['MaxRows'],
+                    $GLOBALS['cfg']['CharEditing'],
+                    $GLOBALS['cfg']['Server']['DisableIS'],
+                    $list_detail_cols[0],
+                    0,
+                ]
+            ),
+            $result
+        );
+        $this->assertContains(
+            $this->callProtectedMethod('getEditTableFooter'),
+            $result
         );
 
     }
@@ -655,7 +691,7 @@ class CentralColumnsTest extends TestCase
     {
         $this->assertInstanceOf(
             'PhpMyAdmin\Message',
-            $this->centralColumns->configErrorMessage()
+            $this->callProtectedMethod('configErrorMessage')
         );
     }
 
@@ -678,12 +714,15 @@ class CentralColumnsTest extends TestCase
             );
         $this->assertEquals(
             array_slice($this->_modifiedColumnData, 1, 1),
-            $this->centralColumns->findExistingColNames(
-                $GLOBALS['dbi'],
-                $GLOBALS['cfg']['Server']['user'],
-                'phpmyadmin',
-                "'col1'",
-                true
+            $this->callProtectedMethod(
+                'findExistingColNames',
+                [
+                    $GLOBALS['dbi'],
+                    $GLOBALS['cfg']['Server']['user'],
+                    'phpmyadmin',
+                    "'col1'",
+                    true,
+                ]
             )
         );
     }
@@ -696,7 +735,13 @@ class CentralColumnsTest extends TestCase
     public function testPMAGetHTMLforTableDropdown()
     {
         $db = 'PMA_db';
-        $result = $this->centralColumns->getHtmlForTableDropdown($GLOBALS['dbi'], $db);
+        $result = $this->callProtectedMethod(
+            'getHtmlForTableDropdown',
+            [
+                $GLOBALS['dbi'],
+                $db,
+            ]
+        );
         $this->assertContains(
             '<select name="table-select" id="table-select"',
             $result
@@ -730,13 +775,13 @@ class CentralColumnsTest extends TestCase
     }
 
     /**
-     * Test for getHtmlForAddCentralColumn
+     * Test for getHtmlForAddColumn
      *
      * @return void
      */
-    public function testPMAGetHTMLforAddCentralColumn()
+    public function testPMAGetHTMLforAddColumn()
     {
-        $result = $this->centralColumns->getHtmlForAddCentralColumn($GLOBALS['dbi'], 20, 0, 'phpmyadmin');
+        $result = $this->centralColumns->getHtmlForAddColumn($GLOBALS['dbi'], 20, 0, 'phpmyadmin');
         $this->assertContains(
             '<table',
             $result