diff --git a/ChangeLog b/ChangeLog
index f9039d847a..cc22dd53aa 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -7,6 +7,7 @@ phpMyAdmin - ChangeLog
 - bug #4080 Overwrite existing file not obeyed
 - bug #3929 Database-specific privileges are not copied when cloning user
 - bug #3997 Error handling in case MySQL extension is missing
+- bug #4089 Moving Columns will alter column definition
 
 4.0.6.0 (2013-09-05)
 - bug #4036 Call to undefined function mb_detect_encoding (clarify the doc)
diff --git a/libraries/structure.lib.php b/libraries/structure.lib.php
index bed7869ef2..2d9fab94a2 100644
--- a/libraries/structure.lib.php
+++ b/libraries/structure.lib.php
@@ -2458,7 +2458,9 @@ function PMA_moveColumns($db, $table)
             unset($data['Extra']);
         }
         $current_timestamp = false;
-        if ($data['Type'] == 'timestamp' && $data['Default'] == 'CURRENT_TIMESTAMP') {
+        if (($data['Type'] == 'timestamp' || $data['Type'] == 'datetime')
+            && $data['Default'] == 'CURRENT_TIMESTAMP'
+        ) {
             $current_timestamp = true;
         }
         $default_type
@@ -2466,7 +2468,7 @@ function PMA_moveColumns($db, $table)
                 ? 'NULL'
                 : ($current_timestamp
                     ? 'CURRENT_TIMESTAMP'
-                    : ($data['Default'] == ''
+                    : ($data['Default'] === null
                         ? 'NONE'
                         : 'USER_DEFINED'));