diff --git a/helpers/content.go b/helpers/content.go
index 167e8de747d..20827889cc2 100644
--- a/helpers/content.go
+++ b/helpers/content.go
@@ -137,6 +137,7 @@ var blackfridayExtensionMap = map[string]int{
 	"autoHeaderIds":          blackfriday.EXTENSION_AUTO_HEADER_IDS,
 	"backslashLineBreak":     blackfriday.EXTENSION_BACKSLASH_LINE_BREAK,
 	"definitionLists":        blackfriday.EXTENSION_DEFINITION_LISTS,
+	"joinLines":              blackfriday.EXTENSION_JOIN_LINES,
 }
 
 var stripHTMLReplacer = strings.NewReplacer("\n", " ", "</p>", "\n", "<br>", "\n", "<br />", "\n")