diff --git a/tbl_structure.php b/tbl_structure.php
index 646b04fd4..263d25ac5 100644
--- a/tbl_structure.php
+++ b/tbl_structure.php
@@ -392,13 +392,15 @@ while ($row = PMA_DBI_fetch_assoc($fields_rs)) {
     </td>
     <td align="center" class="primary">
         <?php
-        if ($type == 'text' || $type == 'blob' || 'ARCHIVE' == $tbl_type || ($primary && $primary->hasColumn($field_name))) {
-            $primary_enabled = false;
+        if ($primary && $primary->hasColumn($field_name)) {
+            $primary_extra_class = ' highlight';
+        } elseif ($type == 'text' || $type == 'blob' || 'ARCHIVE' == $tbl_type) {
+            $primary_extra_class = ' disabled';
         } else {
-            $primary_enabled = true;
+            $primary_extra_class = '';
         }
-            ?>
-        <a class="add_primary_key_anchor<?php echo $primary_enabled ? '' : ' disabled' ?>" href="sql.php?<?php echo $url_query; ?>&amp;sql_query=<?php echo urlencode('ALTER TABLE ' . PMA_backquote($table) . ($primary ? ' DROP PRIMARY KEY,' : '') . ' ADD PRIMARY KEY(' . PMA_backquote($row['Field']) . ')'); ?>&amp;message_to_show=<?php echo urlencode(sprintf(__('A primary key has been added on %s'), htmlspecialchars($row['Field']))); ?>" >
+        ?>
+        <a class="add_primary_key_anchor<?php echo $primary_extra_class ?>" href="sql.php?<?php echo $url_query; ?>&amp;sql_query=<?php echo urlencode('ALTER TABLE ' . PMA_backquote($table) . ($primary ? ' DROP PRIMARY KEY,' : '') . ' ADD PRIMARY KEY(' . PMA_backquote($row['Field']) . ')'); ?>&amp;message_to_show=<?php echo urlencode(sprintf(__('A primary key has been added on %s'), htmlspecialchars($row['Field']))); ?>" >
             <?php echo $titles['Primary']; ?></a>
     </td>
     <td align="center" class="unique">
diff --git a/themes/original/css/theme_right.css.php b/themes/original/css/theme_right.css.php
index 03f424466..da907c5d7 100644
--- a/themes/original/css/theme_right.css.php
+++ b/themes/original/css/theme_right.css.php
@@ -78,6 +78,11 @@ a.disabled {
     filter:             grayscale(1);
 }
 
+a.highlight {
+    cursor:             default;
+    filter:             grayscale(10%) sepia(40%) hue-rotate(50deg) saturate(150%);
+}
+
 dfn {
     font-style:         normal;
 }