diff --git a/chrome/content/zotero/xpcom/attachments.js b/chrome/content/zotero/xpcom/attachments.js
index f58983883..8335e4355 100644
--- a/chrome/content/zotero/xpcom/attachments.js
+++ b/chrome/content/zotero/xpcom/attachments.js
@@ -828,21 +828,21 @@ Zotero.Attachments = new function(){
 					var value = item.getField(field, false, true);
 			}
 			
+			var re = new RegExp("\{?([^%\{\}]*)" + rpl + "(\{[0-9]+\})?" + "([^%\{\}]*)\}?");
+			
 			// If no value for this field, strip entire conditional block
 			// (within curly braces)
 			if (!value) {
-				var re = new RegExp("\{[^%]*" + rpl + "(\{[0-9]+\})?" + "[^%]*\}");
 				if (str.match(re)) {
 					return str.replace(re, '')
 				}
 			}
 			
-			var f = function(match) {
-				var chars = match.match(/{([0-9]+)}/);
-				return (chars) ? value.substr(0, chars[1]) : value;
+			var f = function(match, p1, p2, p3) {
+				var maxChars = p2 ? p2.replace(/[^0-9]+/g, '') : false;
+				return p1 + (maxChars ? value.substr(0, maxChars) : value) + p3;
 			}
 			
-			var re = new RegExp("(\{[^%]*)?" + rpl + "(\{[0-9]+\})?" + "([^%]*\})?");
 			return str.replace(re, f);
 		}