diff --git a/README.md b/README.md
index 7fad8327a..ed60cbb7a 100644
--- a/README.md
+++ b/README.md
@@ -105,6 +105,7 @@ extensions in C and/or Ruby. For a guide on how to use mrbgems, consult the
 - [About the Symbols](doc/guides/symbol.md)
 - [Internal Implementation / About Value Boxing](doc/internal/boxing.md)
 - [Internal Implementation / About mruby Virtual Machine Instructions](doc/internal/opcode.md)
+
 <!-- END OF MRUBY DOCUMENT INDEX -->
 
 ## License
diff --git a/tasks/doc.rake b/tasks/doc.rake
index b755ef52d..d36df8edd 100644
--- a/tasks/doc.rake
+++ b/tasks/doc.rake
@@ -91,7 +91,7 @@ namespace :doc do
     matched = false
     mark_begin = "<!-- BEGIN OF MRUBY DOCUMENT INDEX -->\n"
     mark_end = "<!-- END OF MRUBY DOCUMENT INDEX -->\n"
-    readme1 = readme.sub(/^#{mark_begin}\K.*(?=^#{mark_end})/m) {
+    readme1 = readme.sub(/^#{mark_begin}\n\K.*(?=^\n#{mark_end})/m) {
       matched = true
       doc.each_with_object("") { |d, a|
         summary = File.open(File.join(MRUBY_ROOT, d)) { |f|