diff --git a/app/assets/javascripts/pretty-text/engines/discourse-markdown/bbcode-block.js.es6 b/app/assets/javascripts/pretty-text/engines/discourse-markdown/bbcode-block.js.es6
index c2706b7e664..8276d2318a8 100644
--- a/app/assets/javascripts/pretty-text/engines/discourse-markdown/bbcode-block.js.es6
+++ b/app/assets/javascripts/pretty-text/engines/discourse-markdown/bbcode-block.js.es6
@@ -176,8 +176,9 @@ function findInlineCloseTag(state, openTag, start, max) {
         closeTag = parseBBCodeTag(state.src, j, max);
         if (!closeTag || closeTag.tag !== openTag.tag || !closeTag.closing) {
           closeTag = null;
+        } else {
+          closeTag.start = j;
         }
-        closeTag.start = j;
         break;
       }
     }