diff --git a/ChangeLog b/ChangeLog
index b54aeebe63..f8e55659c9 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -48,6 +48,7 @@ phpMyAdmin - ChangeLog
 - issue #13647 Fixed export of tables with VIRTUAL columns
 - issue #13669 Fixed selecting multiple rows accidentally selects the next row too
 - issue #13513 Fixed edit index Column alignment issue
+- issue #13515 Fixed rendering of add index dialog
 
 4.7.4 (2017-08-23)
 - issue #13415 Remove shadow from the logo
diff --git a/themes/pmahomme/css/common.css.php b/themes/pmahomme/css/common.css.php
index fc8f0edb63..3388b2b9d7 100644
--- a/themes/pmahomme/css/common.css.php
+++ b/themes/pmahomme/css/common.css.php
@@ -2174,7 +2174,7 @@ input#input_import_file {
  */
 #index_frm .index_info input[type="text"],
 #index_frm .index_info select {
-    width: 14em;
+    width: 100%;
     margin: 0;
     box-sizing: border-box;
     -ms-box-sizing: border-box;