diff --git a/lib/rdoc/markdown/literals.kpeg b/lib/rdoc/markdown/literals.kpeg
index 952263b4ae..50ba9e20ce 100644
--- a/lib/rdoc/markdown/literals.kpeg
+++ b/lib/rdoc/markdown/literals.kpeg
@@ -17,7 +17,6 @@
 Alphanumeric      = /\p{Word}/
 AlphanumericAscii = /[A-Za-z0-9]/
 BOM               = "\uFEFF"
-Newline           = /\n|\r\n?|\p{Zl}|\p{Zp}/
+Newline           = /\r?\n|\r\n?/
 NonAlphanumeric   = /\p{^Word}/
-Spacechar         = /\t|\p{Zs}/
-
+Spacechar         = /\t|\p{Blank}/