diff --git a/api/etemplate.php b/api/etemplate.php
index 3033001e8f..65db1d42a9 100644
--- a/api/etemplate.php
+++ b/api/etemplate.php
@@ -64,6 +64,9 @@ function send_template()
 	}
 	elseif(($str = file_get_contents($path)) !== false)
 	{
+		// replace single quote enclosing attribute values with double quotes
+		$str = preg_replace("#([a-z_-]+)='([^']*)'([ />])#i", '$1="$2"$3', $str);
+
 		// fix <menulist...><menupopup type="select-*"/></menulist> --> <select type="select-*" .../>
 		$str = preg_replace('#<menulist([^>]*)>[\r\n\s]*<menupopup([^>]+>)[\r\n\s]*</menulist>#', '<select$1$2', $str);