diff --git a/Markdown.pl b/Markdown.pl
index d1c2fd1..59bd84d 100755
--- a/Markdown.pl
+++ b/Markdown.pl
@@ -646,7 +646,7 @@ sub _HashBTCodeBlocks {
 
     $text =~ s{
 	    (?:(?<=\n)|\A)
-		([ ]{0,$less_than_indent})``(`+)[ \t]*(?:([\w.+-]+)[ \t]*)?\n
+		([ ]{0,$less_than_indent})``(`+)[ \t]*(?:([\w.+-]+[#]?)[ \t]*)?\n
 	     ( # $4 = the code block -- one or more lines, starting with ```
 	      (?:
 		.*\n+