1 files changed, 1 insertions, 1 deletions
diff --git a/spec.txt b/spec.txt
index f19413c..e3f0cd8 100644
--- a/spec.txt
+++ b/spec.txt
@@ -269,7 +269,7 @@ Markdown document.
 
 A line consisting of 0-3 spaces of indentation, followed by a sequence
 of three or more matching `-`, `_`, or `*` characters, each followed
-optionally any number of spaces, forms a [horizontal
+optionally by any number of spaces, forms a [horizontal
 rule](#horizontal-rule). <a id="horizontal-rule"></a>
 
 .