diff --git a/system/Database/Postgre/Forge.php b/system/Database/Postgre/Forge.php
index 2a935e2393bd..47be1b063c8d 100644
--- a/system/Database/Postgre/Forge.php
+++ b/system/Database/Postgre/Forge.php
@@ -110,10 +110,8 @@ protected function _alterTable(string $alterType, string $table, $field)
             }
 
             $nullable = true; // Nullable by default.
-            if (isset($data['null'])) {
-                if ($data['null'] === false || $data['null'] === ' NOT ' . $this->null) {
-                    $nullable = false;
-                }
+            if (isset($data['null']) && ($data['null'] === false || $data['null'] === ' NOT ' . $this->null)) {
+                $nullable = false;
             }
             $sqls[] = $sql . ' ALTER COLUMN ' . $this->db->escapeIdentifiers($data['name'])
                 . ($nullable === true ? ' DROP' : ' SET') . ' NOT NULL';
diff --git a/system/Database/SQLSRV/Forge.php b/system/Database/SQLSRV/Forge.php
index 837f6be49d50..e44624761850 100755
--- a/system/Database/SQLSRV/Forge.php
+++ b/system/Database/SQLSRV/Forge.php
@@ -204,10 +204,8 @@ protected function _alterTable(string $alterType, string $table, $field)
             }
 
             $nullable = true; // Nullable by default.
-            if (isset($data['null'])) {
-                if ($data['null'] === false || $data['null'] === ' NOT ' . $this->null) {
-                    $nullable = false;
-                }
+            if (isset($data['null']) && ($data['null'] === false || $data['null'] === ' NOT ' . $this->null)) {
+                $nullable = false;
             }
             $sqls[] = $sql . ' ALTER COLUMN ' . $this->db->escapeIdentifiers($data['name'])
                 . " {$data['type']}{$data['length']} " . ($nullable === true ? '' : 'NOT') . ' NULL';